Lancets and Methods of Use

ABSTRACT

Lancets and methods of use are provided. Embodiments include lancets including a sleeve mounted to an elongated body having a needle terminating in a sharp tip.

CROSS REFERENCE TO CO-PENDING APPLICATIONS

This Applications claims the benefit of the filing of U.S. ProvisionalPatent Application possessing Ser. No. 60/813,904 filed Jun. 15, 2006,the entire contents of which are incorporated herein by reference, andU.S. Provisional Patent Application possessing Ser. No. 60/877,215 filedDec. 26, 2006, the entire contents of which are incorporated herein byreference. This Application is filed concurrently with the followingrelated applications: application Ser. No. ______ entitled “LANCING ANDMETHODS” (Attorney Docket No. ABB-114-a); application Ser. No. ______entitled “ADJUSTABLE LANCING DEVICES AND METHODS” (Attorney Docket No.ABB-115-A); application Ser. No. ______ entitled “LANCING DEVICES HAVINGLANCET EJECTION ASSEMBLY” (ABB-116-A); and application Ser. No. ______entitled “LANCING DEVICE HAVING DEPTH ADJUSTMENT ASSEMBLY” (AttorneyDocket No. ABB-117-A), the disclosures of which are hereby incorporatedby reference.

BACKGROUND

Lancing devices are typically handheld units that permit users to drawblood for testing and diagnostic purposes. These devices include ahousing with a piercing aperture, a lancet that contains one or moreneedles, and a firing mechanism. The firing mechanism typically includesa spring or other biasing means which can be cocked either by insertionof the lancet or by pulling a cocking handle, for example. Once thelancing device is cocked, it is placed against the user's skin, oftenthe fingertip. The user can then press a trigger to actuate the firingmechanism, which momentarily drives the sharp tip of the needle throughthe piercing aperture to puncture the user's skin and draw blood. Whenthe lancing operation is complete, the user can press a second actuatorto eject the lancet for removal and disposal.

A consideration in the design of lancets is to minimize the discomfortexperienced by users during the lancing process. To this end, somelancing devices include mechanisms to adjust the distance that theneedle sharp protrudes through the piercing aperture, thus regulatingthe depth that the needle penetrates the user's skin. In some cases,these depth adjustment mechanisms include adjustable stops that limitthe forward movement of the lancet during firing. In other cases, depthadjustment mechanisms adjust the tip of the lancing device to reduce orincrease the distance that the needle sharp protrudes from the lancingdevice. One approach for depth adjustment is illustrated in U.S. Pat.No. 5,984,940. A lancet holder is moved axially within a lancing devicehousing to move the needle closer to or farther away from the piercingaperture, thus adjusting penetration depth.

Another consideration in the design of lancing devices is to avoidaccidental needle pricks when inserting and removing lancets from thelancing device. To this end, lancets include safety features such asfrangible tabs which cover the needle sharp prior to insertion in thelancing device. Once the lancet is inserted, the use can break off andremove the frangible tab. Some lancets also include sleeves coaxiallymounted to the main body of the lancet. The sleeve can be positioned sothat it protectively encloses the needle sharp. During the lancingoperation, the main body of the lancet slides through the sleeve toexpose the lancet sharp. After removal of the lancet, however, thesleeve can be locked it its protective position, reducing the likelihoodthat a person handling the use lancet will prick himself or herself.

Lancing devices can draw blood from a user's fingertip or other bodypart. A fingertip is a good testing site because it contains a largenumber of blood vessels and it is therefore easy to draw an adequatequantity of blood from the fingertip. However, fingertips are alsosensitive and users who must frequently draw blood samples mayexperience discomfort from repeated sampling of the fingertips.Therefore, some users also perform lancing operations on parts of thebody, and this is known as alternate site testing or alternate siteincision, also known as “AST”.

To effectively draw blood from an alternate site, it is helpful to havethe needle penetrate the skin more deeply. It is also helpful to have arelatively wide piercing aperture. A wider piercing aperture acts as anexpression ring by allowing the skin to pucker into the aperture'sopening and by compressing a wider area of skin around the incision.When skin protrudes through the aperture into the housing, it is alsomore deeply penetrated by the lancet.

A piercing aperture that is suitably wide for AST lancing may be toowide for finger testing. Thus, some lancing devices provide removableendcaps with different size piercing apertures. A user attaches oneendcap (with a wider piercing aperture) when the lancing device is usedfor AST lancing; and a different endcap (with a more narrow piercingaperture) when the lancing device is used for fingertip lancing.

Another approach has been proposed in which the piercing aperture isadjustable in size, as illustrated in US Pat. Application 2004/0236251.The smaller size is used during the incision, whether on a finger tip oralternate site. Once the incision is made, the piercing aperture isexpanded to provide a larger opening that can be used to express thedesired quantity of blood from an alternate site. The size of thepiercing aperture can be adjusted by moving a reference member into thepiercing aperture, effectively obstructing the opening and providing aflat surface against which the user's skin (finger tip or alternatesite) is pressed for lancing. After the incision is made, the referencemember is retracted to provide an unobstructed, relatively wideexpression opening.

It has also been proposed that the reference member be attached to thelancet itself. During incision, the lancet and the reference member aremoved together toward the piercing aperture to effectively narrow thepiercing aperture. After incision, the reference member and the lancetare retracted to leave the piercing aperture unobstructed. Prior to thelancet's insertion into the lancing device, the reference member can beadjusted relative to the lancet for purposes of regulating thepenetration depth of the needle.

Another consideration in the design of lancing systems is the ease withwhich a lancet can be inserted into the lancing device. It is known thatwhen a lancet is inserted into a lancing device, the force of theinsertion can be used to cock the device. However, if the device isalready cocked, and a lancet was to be inserted, there is some risk thatthe device would discharge during the insertion process and the userwould be accidentally pricked. It is also known to provide a removablecap on the housing to permit insertion of the lancet. However, thisrequires an additional step in the process (namely, removing the cap).It would be desirable to provide a lancing device that can be loadedwithout removal of the cap and that could not be loaded when cocked.

Another consideration in the design of lancets is to minimize thehandling of the lancet by the user during ejecting of the lancet fromthe lancing device. To this end, it is known to provide ejectionmechanisms that include a sliding member that engages the lancet to pushit out of the lancing device. In such cases, it is helpful to restrainthe lancet carrier from forward movement. Known mechanisms for achievingthis use the sliding member to actuate a releasable connector to engagethe lancet carrier and prevent its forward movement, as shown forexample in U.S. Pat. No. 6,197,040. The releasable connector is biasedtowards the ejection slide and away from the lancet carrier and isconfigured so that when the lancet carrier is urged forward, a forcevector is transmitted through the connector to the ejection slide. Thismeans that the slide and the ejector rub against each other with adegree of force, causing friction that is discernable to the user. Itwould be desirable to provide an ejection mechanism that minimizesfriction and force imposed on moving parts to reduce wear.

SUMMARY

Lancets and methods of use are provided. In accordance with someembodiments of the invention, a lancet has an elongated body with aneeded terminating in a sharp tip and a sleeve having a front end and arear end. The sleeve is disposed about at least a portion of theelongated body and movable relative to the elongated body between aforward position in which the sharp tip is protectively surrounded bythe sleeve and a rearward position in which the sharp tip projects fromthe front end of the sleeve. A first locking member extends from theelongated body at a location in between the forward and rearwardpositions. The first locking member has an extended configuration inwhich the locking member engages the sleeve to prevent the sleeve frommoving rearward. The first locking member also has a retractedconfiguration in which the locking member does not engage the sleeve toprevent the sleeve from moving rearward. When the sleeve moves over thefirst locking member, at least a portion of the interior of the sleevesis configured to contain the locking member in its retractedconfiguration.

In accordance with other embodiments of the invention, a lancet isprovided having an elongated body with a needle terminating in a sharptip and a sleeve having a front end and a rear end. The sleeve isdisposed about at least a portion of the elongated body, the sleevelocated at an initial position relative to the elongated body so thatthe sharp tip is disposed within the sleeve. A first locking memberextends from the elongated body at a location outside of the sleeve andhas an extended configuration in which the first locking member engagesthe sleeve to prevent rearward movement of the sleeve and a retractedconfiguration in which the first locking member does not engage thesleeve to prevent the sleeve from moving rearward. A second lockingmember is also provided. The second locking member is axially spacedfrom the first locking member and extends from the elongated body at alocation within the sleeve.

In accordance with other embodiments of the invention a method isprovided for using a lancet that has an elongated body with a needleterminating in a sharp tip, a sleeve disposed about at least a portionof the elongated body and movable relative to the elongated body, and alocking member that has extended and retracted configurations. Themethod includes positioning the sleeve is in a forward position in whichthe sharp tip is protectively surrounded by at least a portion of thesleeve; placing the locking member is in the extended configuration toprevent rearward movement of the sleeve; loading the lancet into alancing device; moving the locking member into the retracted positionbefore firing the lancing device to permit the sleeve to move rearwardover the locking member; and containing the locking member in theretracted position while the sleeve moves over the locking member.

BRIEF DESCRIPTION OF THE DRAWINGS

The description herein makes reference to the accompanying drawingswherein like reference numerals refer to like parts throughout theseveral views, and wherein:

FIG. 1 is a perspective view of a lancing device in accordance with oneembodiment of the invention, including a removable lancet insertedtherein;

FIG. 2 is a left side view of the lancing device of FIG. 1;

FIG. 3 is top plan view of the lancing device of FIG. 1;

FIG. 4 is a bottom plan view of the lancing device of FIG. 1;

FIG. 5 is a perspective view of a lancet for use with the lancing deviceof FIG. 1, including a removable tab and a sleeve in an extendedposition to protectively surround the lancet's needle;

FIGS. 7 a through 7 d are a series of diagrams showing the generaloperation of the lancing device and lancet of FIGS. 1-6;

FIG. 8 is a top plan view of the lancet body of the lancet of FIG. 5;

FIG. 9 is a left side view of the lancet body of FIG. 8;

FIG. 10 is a perspective view of the sleeve in the lancet of FIG. 5;

FIG. 11 is a left side view of the sleeve of FIG. 10;

FIG. 12 is a top plan view of the sleeve of FIG. 10;

FIG. 13 is a isolated perspective view showing detail of the lancet ofFIG. 5, including the rear end of the sleeve and the wings on the lancetbody that prevent rearward movement of the sleeve relative to the lancetbody;

FIG. 14 is a front view of the lancet sleeve of FIG. 10;

FIG. 15 is rear view of the lancet sleeve of FIG. 10;

FIG. 16 is a cross-sectional view of the lancet sleeve of FIG. 10 takenalong the lines 16-16 in FIG. 14;

FIG. 17 is an exploded perspective view of the lancing device of FIG. 1;

FIG. 18 is a cross-sectional view of the lancing device taken along thelines 18-18 of FIG. 3, including the lancet of FIG. 5 as inserted intothe lancing device;

FIG. 19 is a partial perspective view of internal components of thelancing device of FIG. 1 showing drive springs and a portion of thelancet of FIG. 5 as inserted into the lancing device;

FIG. 20 is a perspective view of the left half of the housing of thelancing device of FIG. 1;

FIG. 21 is a perspective view of the right half of the housing of thelancing device of FIG. 1;

FIG. 22 is a left-front perspective view of the lancet carrier of FIG.17;

FIG. 23 is a right-front perspective view of the lancet carrier of FIG.17;

FIG. 24 is a perspective view of the cocking handle of FIG. 17;

FIG. 25 is a front perspective view of the depth adjustment ring anddepth actuator of FIG. 17;

FIG. 26 is rear perspective view of the depth adjustment ring of FIG.17;

FIG. 27 is a perspective view of the trigger of FIG. 17;

FIG. 28 is a top plan view of the trigger of FIG. 27;

FIG. 29 a is a right side view of the trigger of FIG. 26 and itsrelationship with the lancet carrier of FIG. 22 (shown in phantom lines)showing the position of the trigger relative to the housing of thelancing device when the lancing device is cocked;

FIG. 29 b is a right side view of the trigger of FIG. 26 and itsrelationship with the lancet carrier of FIG. 22 (shown in phantom lines)showing the position of the trigger relative to the housing of thelancing device when the lancing device is uncocked;

FIGS. 30 a through 30 d are a series of cut-away right-hand perspectiveviews of the lancing device of FIG. 1, illustrating its cocking andfiring operation;

FIG. 31 is an isolated perspective view of the cap of the lancing deviceof FIG. 1, showing the position of the lancet sleeve when lancing deviceis in finger mode;

FIG. 32 is an isolated perspective view of the cap of the lancing deviceof FIG. 1, showing the position of the lancet sleeve when lancing deviceis in AST mode;

FIG. 33 is a left side view (with housing cut away to reveal internalmechanisms) of the lancing device in AST mode with the cap placed on auser's skin in preparation for lancing operations;

FIG. 34 is a left side (with housing cut away to reveal internalmechanisms) of the lancing device in finger mode with the cap placed ona user's finger in preparation for lancing operations;

FIG. 35 is front perspective view of the AST mode actuator ring of FIG.17;

FIG. 36 is a front view of the AST mode actuator ring of FIG. 35 and itsrelationship with the receiver of FIG. 17 (shown in phantom lines);

FIG. 37 is a rear perspective view of the AST mode actuator of FIG. 35;

FIG. 38 is a front perspective view of the receiver of FIG. 17 and itsrelationship with the AST mode actuator ring;

FIG. 39 is a front perspective sectional view of the receiver of FIG.38, taken along the lines 39-39 in FIG. 33;

FIG. 40 is a rear perspective view of the receiver of FIG. 38 with alancet inserted therein;

FIG. 41 is a rear view of the receiver and lancet of FIG. 40;

FIG. 42 is a front view of the receiver and lancet (shown in phantomlines) of FIG. 40;

FIG. 43 is a left side view of the receiver of FIG. 38;

FIG. 44 is a top plan view of the receiver of FIG. 38;

FIG. 45 is an exploded perspective view of the ejection slide, ejectionactuator and locking member of FIG. 17;

FIGS. 46 a-46 d are a series of cut-away right-hand perspective views ofthe lancing device of FIG. 1, illustrating the operation of the ejectionslide and ejection actuator;

FIG. 47 a is a partial perspective view of a lancing device inaccordance with a further embodiment;

FIG. 47 b is a side elevation of the cap of the lancing device shown inFIG. 47 a;

FIG. 48 is a top plan view of a lancing device in accordance with afurther embodiment;

FIG. 49 is a partial sectional view of a lancing device in accordancewith a further embodiment, taken along the lines 49-49 in FIG. 48;

FIG. 50 a is an isolated perspective view of the lancing device of FIG.1, showing the position of the lancet sleeve protruding beyond thepiercing aperture to adjust penetration depth of the needle sharp;

FIG. 50 b is a left side view (with the housing cut away to revealinternal mechanisms) of the lancing device as shown in FIG. 50 a, withthe lancet sleeve protruding beyond the piercing aperture and placed ona user's skin in preparation for lancing operations;

FIG. 51 is an exploded perspective view of a lancing device inaccordance with a second embodiment of the invention;

FIG. 52 a is a perspective view (with the housing in phantom lines toreveal internal mechanisms) of the lancing device of FIG. 51, showing astopper in an open position;

FIG. 52 b is a perspective view (with the housing in phantom lines toreveal internal mechanisms) of the lancing device of FIG. 52 a, showingthe stopper in a closed position;

FIG. 53 a is a top plan view (with the housing in phantom lines toreveal internal mechanisms) of the lancing device as shown in FIG. 52 a,with the stopper in an open position;

FIG. 53 b is a top plan view (with the housing in phantom lines toreveal internal mechanisms) of the lancing device as shown in FIG. 52 b,with the stopper in a closed position;

FIG. 54 is a perspective view of the stopper of FIGS. 52 a and 52 b;

FIG. 55 is a top plan view of the stopper of FIG. 54;

FIG. 56 is a bottom plan view of the stopper of FIG. 54;

FIG. 57 is front elevation view of the stopper of FIG. 54;

FIG. 58 is left-side elevation view of the stopper of FIG. 54;

FIG. 59 a rear elevation view of the stopper of FIG. 54;

FIG. 59A is partial perspective view of an alternative embodiment of thelancing device of FIG. 51, showing an ejection slide engaging a stopperin an open position;

FIG. 59B is a bottom plan view of an the engagement slide and slide andstopper of FIG. 59A;

FIG. 59C is a top plan view of an engagement slide and stopper inaccordance with an alternative embodiment of the invention, showing thestopper in an open position;

FIG. 59D is a top plan view of the engagement slide and stopper of FIG.59C, showing the stopper in a closed position;

FIG. 60 a is a perspective view (with the housing in phantom lines toreveal internal mechanisms) of the lancing device of FIG. 51, showing atrigger and a locking member in a disengagement position;

FIG. 60 b is a perspective view (with the housing in phantom lines toreveal internal mechanisms) of the lancing device of FIG. 60 a, showingthe locking member in an engagement position;

FIG. 61 a is a top plan view (with the housing in phantom lines toreveal internal mechanisms) of the lancing device as shown FIG. 60 a,with the locking member in a disengagement position;

FIG. 61 b is a top plan view (with the housing in phantom lines toreveal internal mechanisms) of the lancing device as shown in FIG. 60 b,with the locking member in an engagement position;

FIG. 61 c is a top plan view (with the housing in phantom lines toreveal internal mechanism) of the lancing device as shown in FIG. 60 b,with a lancet inserted therein;

FIG. 62 is a front perspective view of the locking member of FIGS. 60 aand 60 b;

FIG. 63 is a rear perspective view of a locking member of FIG. 62;

FIG. 64 is a front elevation of the locking member of FIG. 62;

FIG. 65 is rear elevation of the locking member of FIG. 62;

FIG. 66 is a right side view of the locking member of FIG. 62;

FIG. 67 is a left side view of the locking member of FIG. 62;

FIG. 68 is a top plan view of the locking member of FIG. 62;

FIG. 69 is a bottom plan view of the locking member of FIG. 62;

FIG. 70 is an isolated perspective view of the trigger and lockingmember of FIG. 60 a;

FIG. 71 is a sectional view of the trigger and locking member of FIG. 70taken along the lines 71-71;

FIG. 72 is a perspective view of a carriage assembly of the lancingdevice of FIG. 51;

FIG. 73 is a partial exploded view of the carriage assembly of FIG. 72;

FIG. 74 is a front perspective view of a carriage in the carriageassembly of FIG. 72;

FIG. 75 is a rear perspective view of the carriage in the carriageassembly of FIG. 72;

FIG. 76 is a side elevation of the right half portion of the housingshown in FIG. 51;

FIG. 77 is a front perspective view of a carriage cover of the carriageassembly of FIG. 72;

FIG. 78A is an enlarged perspective view of a depth adjuster of thelancing device shown in FIG. 51, illustrating its interaction with thecarriage assembly of FIG. 72;

FIG. 78B is a rear perspective view of the depth adjuster of FIG. 78A;

FIG. 79A is a partial perspective view of an alternative embodiment ofthe carriage assembly of FIG. 72, showing the engagement of a cockingassembly with the carriage assembly;

FIG. 79B is a sectional view of the carriage assembly as shown in FIG.79A;

FIG. 80 is a front perspective view of the trigger assembly of thelancing device of FIG. 51;

FIG. 81 is an exploded, rearward perspective view of the triggerassembly of FIG. 80;

FIG. 82 is a lancet in accordance with an alternative embodiment of theinvention, showing the lancet sleeve (in sectional) in its fullyextended and locked position;

FIG. 83 is side elevation of showing the lancet sleeve in its retractedposition;

FIG. 84 is an enlarged side elevation of the lancet of FIG. 82;

FIG. 85 is a perspective view of a lancet in accordance with anotherembodiment of the invention;

FIG. 86 is a rear perspective view of the lancet of FIG. 85, with aportion of its sleeve cut away to reveal its interior structure;

FIG. 87 is a front perspective view of the lancet of FIG. 85, with aportion of its sleeve cut away to reveal its interior structure;

FIG. 88 is an ejection locking member in accordance with an alternativeembodiment of the lancing device of FIG. 51;

FIG. 89 is an isolated perspective view of the ejection locking memberof FIG. 88 in relation to the lancet carrier and an ejection actuator;

FIG. 90 is partial top plan view of the carriage assembly of FIG. 51 inwhich the ejection locking member of FIG. 88 has been installed;

FIG. 91 is an isolated perspective view of the carriage assembly andejection locking member of FIG. 90, showing the ejection locking memberforced into its open position by the ejection actuator of FIG. 89; and

FIG. 92 is an isolated perspective view of the carriage assembly andejection locking member of FIG. 90, showing the ejection locking memberin its closed position after the ejection actuator of FIG. 89 has beenslid forward.

FIGS. 93 a-c are front-view perspectives of the sleeve with a crosssection that is one of ovular, circular, and polyglonal.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Overview

Referring to FIGS. 1-4, a lancing system 100 in accordance with anembodiment of the invention is illustrated, including a lancing device102 and removable lancet 104. As explained below, lancing system 100 isoperated by a user to draw a sample of blood or other bodily fluid fromthe body such as for diagnostic purposes. Lancing device 102 includes ahousing 106 with a skin-engaging cap 108 having a piercing aperture 110,a cocking handle 112 used to cock an internal firing mechanism(described below with reference to FIGS. 30 a-30 d), a trigger 114 forfiring the internal firing mechanism, and an ejection slide 115 to ejectlancet 104 from lancing device 102 after use.

Lancing device 102 includes an alternative site testing (“AST”) modeactuator ring 116, a user-actuated assembly or user-controlled actuatorwhich the user may rotate to switch lancing device 102 from a fingermode (in which lancing device 102 is well-suited for drawing blood fromthe user's fingertip) to AST mode (in which lancing device 102 is wellsuited for drawing blood from part of a user's body other than afingertip).

Lancing device 102 includes a depth adjuster 117, which the user mayrotate to limit the forward axial movement of lancet 104 relative to theskin-engaging surface of cap 108, and thereby limit the depth thatlancet 104 penetrates a user's skin.

In this specification, unless otherwise provided, the terms “forward”and “front” mean toward the skin-engaging longitudinal end of lancingdevice 102, and “rear” and “rearward” mean toward longitudinal end oflancing device 102 opposite the skin-engaging end; and term “left” meansthe left side L of lancing device 102 and the term “right” means theright side R of lancing device 102 (as shown in FIG. 3).

As shown in FIGS. 5 and 6, lancet 104 includes a needle 118 whose length(excluding a sharp tip 120) is encased in an elongated lancet body 122.A removable tab 124 includes a flange 126 and an elongated stem 128 thatencases the sharp tip 120 of needle 118. Stem 128 is frangibly attachedto the front end of lancet body 122. A sleeve 130 slides axially over aportion of the lancet body 122 between forward position (as shown inFIG. 5, in which it protectively surrounds the sharp tip 120 of needle118, and a rearward position (as shown in FIG. 6) in which a portion ofsharp tip 120 protrudes beyond the front end of sleeve 130.

The general operation of lancing system 100 is illustrated in FIGS. 7a-7 d. Beginning in FIG. 7 a, the user inserts lancet 104 into lancingdevice 102 through piercing aperture 110. Removable tab 124 (shown inFIG. 7 a with phantom lines seen through the user's thumb) provides aconvenient finger-grip while also protecting the user from exposure tosharp tip 120 and maintains the sterility of the sharp tip 120.

Firm insertion of lancet 104 may cock lancing device 102 (e.g., in ASTmode). After initial use, lancing device 102 may also be cocked bypulling cocking handle 112 (see FIG. 1). The mechanisms for cockinglancing device 102 are explained below.

Once lancet 104 is fully inserted, removable tab 124 extends frompiercing aperture 110. Referring to FIG. 7 b, the user then twists theremovable tab 124 to sever it from lancet body 122 along their frangibleconnection and pulls removable tab 124 off of sharp tip 120. At thistime, sharp tip 120 is enclosed within cap 108. Once removable tab 124is removed, substantially all of lancet 104 can be enclosed by cap 108of housing 106, so that no part of lancet 104 protrudes beyond piercingaperture 110 by an amount sufficient to displace the user's skin fromthe skin engaging surface of cap 108.

With lancet 104 inserted into lancing device 102 and lancing device 102having been cocked, the user places the front surface of sleeve 130 ofskin-engaging cap 108 onto his or her finger or other body part andpresses trigger 114. The depression of trigger 114 actuates a firingmechanism within housing 106 (described below) to momentarily thrustneedle 118 forward through piercing aperture 110.

Referring to FIG. 7 c, after lancing device 102 is fired, the userslides ejection slide 115 on the underside of housing 106 in thedirection of arrow A to partially eject lancet 104 through piercingaperture 110 of cap 108. The mechanisms for ejection are described belowwith reference to FIGS. 45 and 46. As the user slides ejection slide 115in the direction of arrow A, the ejection slide engages an ejectionactuator 121 inside housing (shown in FIG. 7 c with phantom lines; seealso FIGS. 45 and 46) to push lancet sleeve 130 into its forwardposition relative to lancet body 122 so that lancet sleeve 130 surroundssharp tip 120 in a protective closure (as shown in FIG. 5) and thefront-most portion of lancet sleeve 130 projects out of piercingaperture 110 for withdrawing engagement by a user's finger tips. Lancet104 can also be expelled from lancet device 102 by force of gravityafter operation of ejection slide 115, without the user having to touchlancet 104.

As shown in FIG. 7 d, grasping the lancet sleeve 130, the user removeslancet 104 from lancing device 102. Upon ejection, lancet sleeve 130 islocked into its protective position by the extension of locking membersor wings 132 a, 132 b from lancet body 122 (as shown in FIG. 5), thusreducing the possibility the a user will accidentally prick himself orherself on sharp tip 120.

Lancing system 100 can also be used in a kit which includes test stripsand an analyzer. After lancing system 100 is operated to draw blood, theuser applies the bead of blood to the test strip and inserts the teststrip into the analyzer for assessment of blood composition, such aslevels of glucose.

Lancet

Referring to FIGS. 8-16, the construction of lancet 104 is described,beginning with lancet body 122. Guidance ribs 134 are formed on the topand bottom sides of lancet body 122 near its front end. Guidance ribs134 extend radially from lancet body 122, with the elongated extent ofguidance ribs 134 running parallel to the major axis of lancet body 122.

The diameter of lancet body 122 tapers to form a conical rear end 136and a neck 138 which define therebetween a mounting bulb 140.

Wing wells 142 a and 142 b are formed in left and right lateral surfacesof lancet body 122, respectively, near the mid-section of lancet body122. Extending from each wing well 142 a, 142 b is one of lockingmembers, or wings 132 a, 132 b. Each of wings 132 a, 132 b has a short,stiff base portion 144 extending radially out from lancet body 122 and aplanar flexion member 146 having a wingtip 148 extending in generallyforward direction but at an acute angle, which in this case isillustrated as approximately 45° away from the major axis of the lancetbody 122 when in the extended configuration. Wings 132 a, 132 b may bemolded as part of lancet body 122.

Wings 132 a, 132 b can flap into a retracted configuration by foldingplanar flexion members 146 from their extended position shown in FIG. 8to a retracted position in which flexion member 146 is folded forward byapproximately 45° so that flexion member 146 is substantially disposedwithin its corresponding one of wing wells 142 a, 142 b. Planar flexionmembers 146 are flexible and resilient in that they can be folded intowing wells 142 a, 142 b under the influence of a lateral force, but willreturn to their outward extended configuration when that force isremoved.

Other suitable locking members may be used as an alternative to wings132 a, 132 b. These other suitable locking members include, but are notlimited to, pivoting members that pivot rather than fold into the wingwells, studs that extend out from the lancet body that can be pushedinto a retracted position into a well in the lancet body, or barbs.

FIGS. 10-16 illustrate lancet sleeve 130 in more detail. Sleeve 130 isgenerally tubular in construction with a front end 150 and a rear end152 and defining an elongated inner chamber 154 there between. Sleeve130 is divided into a front portion 156 and a rear portion 158. Fourouter guidance ribs 160 a through 160 d project radially from the frontportion 156 of sleeve 130 at 90° intervals, extending along thelongitudinal extent of front portion 156. Front ends 162 a through 162 dof guidance ribs 160 a-160 d have a slight bevel. Although sleeve 130 istubular, sleeve 130 can be made with different sectional shapes or slots(to reduce the material used to manufacture sleeve 130). In additionalembodiments, the sleeve 130 has a cross section that is one ofpolygonal, circular and ovular, as shown in FIGS. 93 a-c.

An annular flange 164 circumscribes sleeve 130 between its front portion156 and rear portion 158. The front face of annular flange 164 defines amounting shoulder 166 and the rear face of annular flange 164 defines anejection shoulder 168. As further explained below, mounting shoulder 166provides a surface permitting a receiver 170 (see FIG. 17) that isinternal to housing 106 to engage sleeve 130, and ejection shoulder 168provides a surface for ejection actuator 121 (also internal to housing106; see FIGS. 17 and 18) to engage sleeve 130.

In rear portion 158, sleeve 130 is generally hexagonal in cross section(except for its rear end 152, as explained below) and defines lowerplanar faces 172 a and 172 f, upper planar faces 172 c and 172 d andlateral planar faces 172 b and 172 e. Lateral planar faces 172 b and 172e can be used during manufacturing to position sleeve for installationon lancet body. Also, as explained below, when lancet 104 is insertedinto receiver 170, lower planar faces 172 a and 172 f and upper planarfaces 172 c and 172 d mate with corresponding surfaces inside receiver170 to orient lancet 104 within lancing device 102, as shown in FIG. 42.

As best seen in FIG. 13, the exterior shape of sleeve 130 at its rearend 152 is that of a cylinder 174 with its top and bottom surfacessheared off to form planar surfaces 176 a and 176 b. Planar surfaces 176a and 176 b are contiguous with lateral planar faces 172 b and 172 e,respectively. Lower planar surfaces 172 a and 172 f terminate in beveledcorner 178 a on the left side of cylinder 174 and upper planar surfaces172 c and 172 d terminate in beveled corner 178 b on the right side ofcylinder 174. Beveled corners 178 a, 178 b act as guiding surfaces torotate lancet sleeve 130 into its proper orientation as it is insertedinto receiver 170.

The inner chamber 154 of sleeve 130 is sized and configured to allowlancet body 122 to be snugly coaxially disposed within sleeve 130. Thesleeve 130 has a width of less than 5 mm. As best seen in FIGS. 14-16,inner chamber 154 is generally cylindrical with upper and lower grooves180 extending longitudinally through sleeve at the top and bottom ofinner chamber 154, respectively. Grooves 180 are each sized andpositioned to receive guidance ribs 134 of lancet body 122 in slidingengagement. As best seen in the sectional view of FIG. 16, each ofgrooves 180 extends from front end 150 of sleeve 130 to one of backstops182 that are displaced from rear end 152 of sleeve 130.

Each of guidance ribs 134 of lancet body 122 fits into one of grooves180, permitting sleeve 130 to slide axially forward over lancet body 122to an extended protective position (in which front portion 156 of sleeve130 surrounds sharp tip 120, as shown in FIG. 5) and backward overlancet body 122 to a retracted position (in which sharp tip 120 extendspast the front end 150 of sleeve 130, as shown in FIG. 6). Back stops182 engage one of rearmost ends of guidance ribs 134 to prevent sleeve130 from sliding off the front of lancet body 122.

The cylindrical contour of inner chamber 154 is further modified by theinclusion of elongated guide surfaces which are wing engagement surfaces184, a pair of wide, shallow lateral grooves on opposing lateral sidesof sleeve 130 that extend the length of sleeve 130.

The function of wing engagement surfaces 184 is explained as follows.When wings 132 a, 132 b are in the extended configuration, theirwingtips 148 span a distance greater than the diameter of inner chamber154. If sleeve 130 moves rearward relative to lancet body 122 from itsprotective extended configuration (shown in FIGS. 5 and 13), wingtips148, if extended, will engage the rear end 152 of lancet sleeve 130,blocking further rearward movement of sleeve 130 and in effect lockingsleeve 130 in its protective extended position, as shown in FIG. 5.

However, when wings 132 a, 132 b are in their retracted configuration(that is, folded into wing wells 142 a, 142 b as shown in FIG. 6), theydo not extend beyond the diameter of inner chamber 154, so that sleeve130 can slide axially over the wing wells 142 a, 142 b withoutinterruption. As sleeve 130 slides over wings 132 a, 132 b, each of thewings (now folded into wing wells 142 a, 142 b) brushes along thelongitudinal extend of wing engagement surfaces 184, or elongated guidesurfaces as shown in FIG. 6. These surfaces contain the locking memberor wings 132 a, 132 b in their retracted configuration when the sleeve130 moves over the wings.

Sleeve 130 and wings 132 a, 132 b can be separate components, as shownabove, so that sleeve 130 can be in space-apart relation to wings 132 a,132 b. This permits sleeve to be moved over a wider range of lancet body122 to accommodate operation of lancing device 102 in AST and fingermodes, as described below.

Note that for simplicity in illustration, the relative axial movement ofsleeve 130 and lancet body 122 is described solely in terms of sleeve130 moving over the body 122. In operation of lancing device 102, mostnotably during firing of lancet 104, this same relative movement isachieved by moving the lancet body 122 while the sleeve 130 remainsstationary. However, the mechanical interaction between sleeve 130 andbody 122 in that case is still as described above.

Internal Construction of Lancing Device

Referring to FIGS. 17 and 18, the internal construction of lancingdevice 102 is shown. Receiver 170 is coupled to AST mode actuator ring116 and engages lancet sleeve 130 to move lancet sleeve in response tomovement of AST mode actuator ring 116. A slidable lancet carrier 208engages lancet body 122. A drive spring 210 propels the lancet carrier208 toward piercing aperture 110 to drive lancet needle 118 to piercethe user's skin or other bodily tissue. A return spring 212 propelslancet carrier 208, removing needle's sharp tip 120 out of the user'sskin after piercing. The combination of lancet carrier 208 and at leastdrive spring 210 acts as a lancet holding assembly to hold and movelancet. An ejection actuator 121 is coupled to ejection slide 115 andejects lancet 104 from lancing device 102 in response to movement by theuser of ejection slide 115. Also located within housing are portions ofcocking handle 112 and depth adjuster 117 as described below.

These components of lancing device 102 will now be described.

Housing

FIGS. 20 and 21 illustrate the construction of housing 106. Housing 106defines an elongated hollow barrel having a front aperture 200, rearaperture 201, AST mode actuator aperture 202 (through which a portion ofAST mode actuator ring 116 extends and trigger aperture 203 (throughwhich a portion of trigger 114 extends). Note that for ease ofmanufacture, housing 106 may be formed of a conjoined left half 206 andright half 204 as shown in FIGS. 20 and 21, respectively.

Referring to FIG. 20, the left half 206 of housing 106 includes a pairof elongated, spaced-apart guides 214 defining there between a lancetcarrier left-hand guide track 216.

Left half 206 also includes near its front end a pair of semi-annularflanges 218 a. Flanges 218 a define the left half of shoulders 220 thatare spaced apart slightly more than the width of AST mode actuator ring116, so that AST mode actuator ring 116 can be mounted for rotationbetween shoulders 220 of housing 106, as shown in FIG. 18. The frontmost of flanges 218 a also defines the left half of front aperture 200of housing 106.

An elongated slot 222 is formed near the lower front end of left half206. As explained below, elongated slot 222 provides a guide track forejection actuator 121 as it slides axially to eject lancet 104 fromlancing device 102 and also permits intercoupling of ejection slide 115and ejection actuator 121 through housing 106. Adjacent to and justabove elongated slot 222 is an elongated member 224 that functions as anadditional guide for the movement of ejection actuator 121.

A rearward portion of left half 206 has a reduced diameter to define asemi-annular rear flange 226 a from which extends the left half of adistal mounting portion 228. As best seen in FIG. 1, cocking handle 112and depth adjustment ring 117 are mounted to distal mounting portion228. Near the rear end of distal mounting portion 228 is a semi-annularflange 230 a defining the left half rear aperture 201, which has adiameter narrower than the rest of mounting portion 228 to provide anannular guide ring for cocking handle 112.

Referring to FIG. 21, right half 204 of housing 106 includes a pair ofelongated, spaced-apart guides 234 running along a portion of the upperlongitudinal extent of right half 204. Spaced apart guides 234 definethere between the lancet carrier right-hand guide track 236.

Right half 204 also includes near its front end a pair of semi-annularflanges 218 b aligned with flanges 218 a of left half 206. Flanges 218 bdefine the right half of shoulders 220, as explained above in referenceto left half 206. The front-most of flanges 218 b also defines the righthalf of front aperture 200 of housing 106.

An elongated slot 240 for ejection slide 115 and ejection actuator 121is formed near the lower front end of right half 204. Slot 240 is inalignment with and performs the same function as its counter-part slot222 of left half 206.

Below lancet carrier right hand guide track 236 are positioned a drivespring boss 244 on which drive spring 210 is mounted (as best seen inFIG. 19) and a return spring boss 246 on which return spring 212 ismounted (as best seen in FIG. 19). Each of bosses 244 and 246 is hollowand open ended for mating engagement with its corresponding one ofsupport bosses 248 and 249, respectively, projecting from left half (seeFIG. 20).

Positioned forward of and slightly above drive spring boss 244 is adrive spring stop 250 in the form of a finger. Positioned rearward ofand slightly above return spring boss 246 is return spring stop 252 alsoin the form of a finger. The operations of drive spring stop 250 andreturn spring stop 252 are explained below in reference to FIGS. 30 athrough 30 d.

Positioned near the upper end of right half 204 just rearward of triggeraperture 203, is an open-ended cylindrical trigger pivot well 253, onwhich trigger 114 is pivotally mounted as described below in referenceto FIGS. 27 through 29.

A rearward portion of right half 204 has a reduced diameter to define asemi-annular annular rear flange 226 b from which extends the right halfof distal mounting portion 228. Near the rear end of distal mountingportion 228 is a semi-annular flange 230 b defining the right half ofrear aperture 201 of housing 106.

Cap

Referring to FIGS. 1 through 3, attached to the front end of housing 106is cap 108. Cap 108 may be opaque (so that users do not see the sharptip 120). Cap 108 provides protective closure around sharp tip 120 whenlancet 104 is inserted into lancing device 102. Referring to FIG. 31,cap 108 also includes an annular skin-engaging proximal surface 254 thatforms a compression ring 256 about piercing aperture 110. Although cap108 may be constructed in a variety of sizes and configurations, incertain embodiments piercing aperture 110 may be about 5 mm to about 15mm in diameter and skin-compression ring 256 may have a width of about 1mm to about 3 mm. The operation of skin-compression ring 256 andpiercing aperture 110 will be described as follows in relation to ASTmode actuator ring 116. Skin compression ring may be circular or haveother shapes and need not be continuous or completely annular.

Cap 108 can be removable from the front end of housing 106 to permitcleaning of the interior of lancing device 102. To permit its removal,cap 108 can be threadably connected to housing 106 or connected via snapfit, for example. However, during operation of lancing device 102 it isnot necessary to remove cap 108. Alternatively, cap 108 can bepermanently attached to or integrally molded with housing 106. Lancet104 can be loaded into lancing device through piercing aperture 110while cap 108 remains attached to housing 106. As explained below, thesame cap 108 can be used when lancing device 102 is operated in bothfinger mode and AST mode. In other words, cap 108 need not be replacedto accommodate use of lancing device in finger and AST modes.

Lancet Carrier

Referring to FIGS. 22 and 23, lancet carrier 208 is described in moredetail. Lancet carrier 208 has the primary function of holding lancet104 as lancet 104 is inserted, fired and ejected from lancing device102. Lancet carrier 208 includes a main body 258 defining at is frontend a mouth 260 comprised of an upper jaw 262 and a lower jaw 264. Upperand lower receiving jaws 262 and 264 are formed of flexible elongatedplanar members extending forward from main body 258 of lancet carrier208. The tips of each of upper and lower jaws 262 and 264 include one oftwo opposing inwardly projecting snaps 268. Unless a force is applied tourge jaws 262 and 264 apart, jaws 262 and 264 will tend to remain in theclosed position shown in FIGS. 22 and 23. When jaws 262 and 264 are inthe closed position, distance d between snaps 268 is less than thediameter of the mounting bulb 140 of the lancet body 122. It will beappreciated that lancet carrier 208 operates as part of a lancet holdingassembly that engages the lancet needle at a position that isindependent of the position of receiver 170.

Referring to FIGS. 18 and 19, as lancet 104 is inserted into lancingdevice 102, lancet body 122 extends through receiver 170 until itsconical rear end 136 abuts mouth 260. The distal tip of conical rear end136 is sufficiently narrow to slide easily between the snaps 268 ofupper and lower jaws 262, 264. However, as the conical rear end 136 isplunged further into mouth 260, portions of conical rear end 136 havinga wider diameter enter mouth 260 and force apart upper and lower jaws262, 264 until the mounting bulb 140 of body passes through jaws 262,264. Once mounting bulb 140 passes, jaws snap shut around neck 138,whose narrower diameter creates a recess that engages snaps 268. Lancetcarrier 208 will thus hold lancet body 122 until a sufficient forwardforce is applied to expel lancet body from mouth 260.

A push plate 270 extends from main body 258 near in the rear of mouth260 so that push plate 270 abuts the tip of conical rear end 136 oflancet body 122 when lancet body 122 is fully inserted into mouth 260.

Referring to FIG. 22, the top surface 272 of lancet carrier 208 has anintermediately positioned recess 274 that defines a backwall 276. To therear of recess 274, top surface 272 provides a platform 278. Recess 274and platform 278 provide surfaces by which trigger 114 engages lancetcarrier 208, as described below.

Referring to FIG. 23, a carrier drive spring engagement boss 280 andcarrier return spring engagement boss 282 extend from the left side oflancet carrier 208. Carrier drive spring engagement boss can extend outfrom push plate 270. As explained below in reference to FIGS. 30 athrough 30 d, bosses 280 and 282 engage drive spring 210 and returnspring 212, respectively, during the firing of lancing device 102. Drivespring engagement boss 280 has a rounded contour on its rearward-facingside. Return spring engagement boss 282 has a rounded contour on itsforward facing side.

An elongated horizontal slot 284 is provided in rearward half portion oflancet carrier 208, below platform 278. Slot 284 defines horizontalsidewalls 286 and 288, a back wall 290 and a front wall 292. As will beexplained below with reference to FIGS. 30 a through 30 d, slot 284receives engagement members of cocking handle 112 and depth adjustmentring 117.

Carrier drive and return spring engagement bosses 280 and 282 aredisposed within lancet carrier right-hand guide track 236 in housing 106(see FIG. 21) to permit lancet carrier 208 to slide axially withinhousing 106 along guide track 236. A guide boss 294 extends laterallyfrom the left hand side of lancet carrier 208 just below recess 274(FIG. 20). Guide boss 294 engages lancet carrier left hand guide track216 in housing 106 (See FIG. 20) to permit lancet carrier 208 to slideaxially within housing 106 along guide track 216. The axial slidingmovement of lancet carrier 208 within housing 106 permits lancet carrier(and thus lancet) to be moved under the operation of drive spring 210 toeffectuate the cocking, firing and skin-piercing operations of lancingdevice 102, as described below.

Cocking and Firing

Referring to FIGS. 19 and 21, a drive member has a drive spring 210torsion spring mounted about drive spring boss 244 of housing 106. Afirst terminus of drive spring 210 forms a tine 300 that engages therounded contour of drive spring engagement boss 280. The opposingterminus of drive spring 210 forms a tine 302 that is received by drivespring retention notches 304 on return spring boss 246 of housing 106(FIG. 19). When drive spring 210 is cocked (as described below), iturges the lancet carrier 208 toward piercing aperture 110 to extendsharp tip 120 into the user's skin.

Referring to FIGS. 19 and 23, return spring 212 is a torsion springmounted about return spring boss 246 extending from housing 106. A firstterminus of return spring 212 is a tine 306 that engages the roundedcontour of a return spring engagement boss 282 on the lancet carrier208. The opposing terminus of return spring 212 is an anchor tine 308that is engaged return spring stop 252 extending from housing 106. Whenreturn spring 212 is tensioned (as described below), it urges lancetcarrier 208 away from piercing aperture 110 to retract the sharp tip 120from the user's skin.

Referring to FIG. 24, cocking handle 112 has a generally cylindricalhandle portion 312 sized to fit over rear aperture 201 of housing 106,and an elongated rod 314 extending from handle portion 312. The forwardtip of rod 314 terminates in an L-shaped engagement hook 316, which ispositioned in slot 284 of lancet carrier 208 as shown in FIG. 30 a. Asbest seen in FIGS. 30 a-d, cocking handle 112 is located over rear endof housing 106, with elongated rod 314 passing into the interior ofhousing 106 through rear aperture 201. The constricted diameter of rearaperture 201 restrains elongated rod 314 to axial movement withinhousing 106.

A compression spring (not shown) may be placed at rear aperture 201 ofhousing 106, with one end of the spring secured to housing 106 and theother end secured to handle portion 312 to bias handle portion 312toward housing.

As shown in FIGS. 27 through 29, trigger 114 has an elongated body 318with opposing laterally extending pivots 320. A user-actuated triggerbutton 322 is located at the front end of elongated body 318. A tooth324 depends from the rear end of elongated body 318 and engages the topof lancet carrier 208 as shown in FIG. 29 b.

Trigger 114 is mounted to the housing 106 with the trigger button 322extending through trigger aperture 203 in housing 106 (see FIG. 29 a)and each of pivots 320 mounting to one of wells 253 formed in theinterior of housing 106.

Trigger button 322 includes a colored band 325 circumscribing the bottomportion of trigger button 322 and can have a color that contrasts withthe color of the remainder of trigger button 322. For example, triggerbutton 322 can be black with a colored band 325 that is red. Coloredband 325 is visible to a user when the trigger button 322 extends fullythrough trigger aperture 203. Colored band 325 is at least partiallyobscured from the user's view by the housing 106 when trigger button 322does not fully extend through the trigger aperture 203, as shown in FIG.29. If desired, other indicia may be used instead of a colored band,including for example graphics or alphanumeric symbols, which are placedalong the bottom portion of trigger button 322.

A biasing leaf element 326 extends from the rear end of trigger 114 andurges downward the rear end of elongated body 318 so as to urge tooth324 toward lancet carrier 208 and, in see-saw fashion, urges triggerbutton 322 upward. By pressing trigger button 322 down, the user canovercome the force of biasing leaf element 326 and swing tooth 324upward away from lancet carrier 208 to fire lancing device 104 whencocked.

Referring to FIGS. 29 a and 29 b, the position of trigger 114 relativeto housing 106 is illustrated when lancing device 102 is in its cockedand uncocked positions, respectively. As shown in FIG. 29 a, whenlancing device is cocked, trigger button 322 extends through triggeraperture 203 in housing 106 so that colored band 325 is visible to user,to provide both tactile and visual feedback to the user that lancingdevice 102 is cocked. As shown in FIG. 29 b, when lancing device 102 isuncocked, trigger button 322 is withdrawn so that it does not extendthrough trigger aperture 203 and the top surface of trigger button 203is even with the surface of housing 106. In this position, colored band325 is not visible. When trigger button 322 is withdrawn and coloredband 325 is not visible, the user has both tactile and visual feedbackthat lancing device 102 is not cocked.

Referring to FIGS. 30 a through 30 d, the cocking and firing process oflancing device 102 is described in more detail. Lancet carrier 208 canhave three principal positions relative to drive spring 210 and returnspring 212: the neutral position (FIG. 30 a), cocked position (FIG. 30c), and the extended firing position (FIG. 30 d).

Referring to FIG. 30 a, in its neutral position, lancet carrier 208 ispositioned so that both drive and return springs 210 and 212 are in arelaxed state. The neutral position is the position that lancing device102 returns to after it has been fired.

In the neutral position, tooth 324 of trigger 114 rests on platform 278of lancet carrier 208 (as also shown in FIG. 29 b). This forces triggerbutton 322, in see-saw fashion, to withdraw from the trigger aperture203 in the housing 106 so that trigger button 322 either flush withexterior of housing 106 or can extend only partially outside housing106. In either case, colored band 325 on trigger button 322 is notvisible to the user, as also shown in FIG. 29 b.

In the neutral position, cocking handle 112 is at rest on the rear endof housing 106, cocking rod 314 is fully extended into housing 106 andcocking hook 316 is disposed in slot 284 some distance removed frombackwall 290.

Referring to FIG. 30 b, the user cocks lancing device by pulling cockinghandle 112 away from housing. As cocking handle 112 is pulled, cockingrod 314 is drawn in a rearward direction through rear aperture 201 andcocking hook 316 slides rearward through slot 284 until cocking hookabuts backwall 290. With cocking hook 316 abutting backwall 290,continued pulling of cocking handle 112 pulls lancet carrier 208rearward relative to its neutral position so that drive springengagement boss 280 pushes tine 300 of drive spring 210 into a tensionedor cocked position.

Referring to FIG. 30 c, when lancet carrier 208 is in a fully cockedstate, the lancet carrier 208 is moved rearward so that its recess 274is positioned under tooth 324 of trigger 114. Under the urging of biasleaf 326, tooth 324 extends into recess 274 and engages back wall 276,holding lancet carrier 208 in its fully cocked position. A more detailedview of the engagement of tooth 324 into recess 274 is shown in FIG. 29a.

As bias leaf 326 pushes tooth 324 into lancet carrier recess 274, iturges trigger button 322 upward in the direction of Arrow A to fullyextend through trigger aperture 203. In this position, colored band 325about the base of the trigger button 322 is visible to the end user toindicate that the lancing device 102 is cocked, as also shown in FIG. 29a.

When the user depresses the trigger button 322 (in the direction ofarrow B), the force of biasing leaf 326 is overcome, and tooth 324swings upward (in the direction of arrow C) out of recess 274 in lancetcarrier 208. Once tooth 324 is removed from recess 274, cocked lancetcarrier 208 is no longer restrained and it accelerates forward under theforce of drive spring 210 toward its extended piercing position as shownin FIG. 30 c.

Referring to FIG. 30 d, lancet carrier 208 is shown in its extendedpiercing position after having been fired (that is, released from itscocked position) by the user's actuation of trigger 114. In thisextended piercing position, drive spring 210 (by action of tine upondrive spring engagement boss 280 (not shown), has propelled lancetcarrier 208 toward piercing aperture 110 in cap 108. As a result, sharptip 120 protrudes momentarily from the piercing aperture 110 in the cap108 to pierce the user's skin.

In the extended piercing position, lancet carrier 208 is positionedforward of the neutral position, so that return spring engagement boss282 pushes tine 306 of return spring 212 into a tensioned position. Inthis tensioned position, return spring tine 306 urges the lancet carrier208 rearward, away from the user's skin back toward the neutral positionshown in FIG. 30 a, thus withdrawing sharp tip 120 from the skin.

Note that during the cocking and firing operations described above,lancet sleeve 130 can remain stationary.

As explained above, lancet carrier 208 can also be cocked by insertionof lancet 104 while lancing device 102 is in AST mode. When lancet 104is inserted, conical rear end 136 of lancet body 122 pushes lancetcarrier 208 rearward to its cocked position, where tooth 324, of trigger114, extends into recess 274 of lancet carrier 208 to hold lancetcarrier in its cocked position.

It will be appreciated that springs 210 and 212 and trigger 114 comprisea user-actuated drive mechanism. Any other suitable drive mechanisms canbe employed, including for example, coil springs, electromagneticdrives, or impact hammer arrangements. It will be further appreciatedthat the trigger mechanism employed may be any other suitable triggeringmeans, including for example pulley movement actuated by rotating orpulling the lancet device or a sliding mechanism.

Depth Adjustment

Referring to FIGS. 25 and 26, the function of depth adjuster 117 is tolimit the forward axial movement of sharp tip 120 relative to theskin-engaging surface 254 of cap 108, and thereby limit the depth thatsharp tip 120 penetrates the user's skin.

Depth adjuster 117 includes a depth adjustment ring 330 mounted forrotation about the distal mounting portion 228 of housing 106 as shownin FIGS. 1-4. The forward interior portion of depth adjustment ring 330has threads 332, and the rearward interior portion depth adjustment ring330 has circumferentially arranged detents 334. A protrusion (not shown)on portion 228 of housing 106 engages detents 334 to provide discretesettings for depth adjustment ring 330 as it rotates about distalmounting portion 228.

The exterior of depth adjustment ring 330 is accessible to users forrotation and includes indicia 338 and a knob 339 to facilitatemanipulation by the user. As depth adjustment ring 330 rotates, indicia338 are visible to the user to indicate the resulting depth setting.

Depth adjuster 117 also includes a depth adjuster actuator 340, whichhas an generally Z-shaped chassis 342. A finger 344 projects from therear end of Z-shaped chassis 342 and is sized to fit in threads 332. Aguide surface 346 extends from an intermediate portion of Z-shapedchassis 342. A depth stop 348 projects from the forward end of Z-shapedchassis.

As best seen in FIG. 30 d, depth adjuster actuator 340 is installedwithin housing 106 so that finger 344 is disposed with threads 332,guide surface 346 is adjacent to and parallel with guide surface 350,352 of housing, and depth stop 348 is disposed within slot 284 of lancetcarrier 208.

As depth adjustment ring 330 rotates, finger 344 follows threads 332causing depth adjustment actuator 340 to move axially forward andrearward (depending on the direction that depth adjustment ring 330 isrotated). This motion in turn causes depth stop 348 to slide forward andrearward relative to slot 284 (depending on the direction that depthadjustment ring 330 is rotated). The motion of depth adjuster actuator340 is limited by the length of slot 284 or alternatively by the lengthof threads 332. There is now a pair of stops that limit the rotation ofthe ring 330.

Guide surfaces 346 and depth stop 348 slide along adjacent planarparallel guide surfaces 350 and 352, respectively, extending fromhousing 106 (see FIG. 20) interact to limit motion of depth actuator 340to axial (as opposed to lateral) movement.

When the user depresses trigger 114 when lancing device is in its cockedstate, drive spring 210 propels lancet carrier 208 forward to extendsharp tip 120 through piercing aperture 110 and into the user's skin.During forward motion of lancet carrier 208, depth stop 348 remainsstationary so that eventually the back wall 290 of slot 284 will impactdepth stop 348, as shown in FIG. 30 d. This impact prevents furtherforward movement of lancet carrier 208 relative to housing 106 and thuslimits the penetration of sharp tip 120. By rotating depth adjustmentring 330, the user can selectively position depth stop 348 relative tolancet carrier 208 (as indicated by indicia 338) and thus controlpenetration depth of sharp tip 120.

AST Mode Adjustment

Lancing device 102 operates in AST mode and finger mode. In AST mode,lancing device 102 is configured for use with fleshy parts of the bodysuch as a thigh or forearm. In finger mode, lancing device 102 isconfigured for use with a fingertip.

Referring to FIGS. 31 and 33, operation of lancing device 102 in an ASTmode is shown. In AST mode, cap 108 is placed against a fleshy part ofthe body. Compression ring 256 engages the user's skin, causing it topucker inside the relatively wide piercing aperture 110. The puckeredflesh is then pierced by sharp tip 120, as shown in FIG. 33, allowingthe user to apply pressure before, during and after lancing to help withblood acquisition. Clearance prevents wicking of the blood drop andallows the user to see when sufficient blood has been acquired.

Referring to FIGS. 32 and 34, operation of lancing device 102 in afinger mode is shown. In finger mode, sleeve 130 is slid toward thefront end of the cap 108 (by means of AST mode actuator ring 116 andreceiver 170, as described below), so that the front end 150 of sleeve130 is interposed in or obstructs a portion of piecing aperture 110,providing in conjunction with compression ring 256, a skin-engagingcontour that is suitable for placement against a finger. The obstructionof the piercing aperture 110 that is effected by sleeve 130 need not becomplete; rather sleeve 130 can be placed in proximity to piercingaperture 110 so that the user's skin will encounter sleeve 130 when cap108 is placed against the user's body prior to firing lancing device102, and consequently, the user's skin will not be able to pucker intocap 108 through piercing aperture 110, at least to the same extent asthe skin could pucker if sleeve 130 were not obstructing piercingaperture 110. When sleeve 130 obstructs piercing aperture 110, front end150 of sleeve 130 can be substantially coplanar with compression ring256.

Referring to FIGS. 33 and 34, sleeve 130 is held by receiver 170, whichin turn is controlled in cam-like fashion by AST mode actuator ring 116.To transition between AST and finger mode, the user rotates AST modeactuator ring 116, which drives the receiver 170 (and hence the lancetsleeve 130) axially toward or away from the skin-engaging surface 254 ofthe cap 108 (depending on which direction the user rotates AST modeactuator ring 116). It will be seen that AST mode actuator ring 116operates as a user-actuated assembly or user-controlled actuator totransition the lancing device between finger mode and AST mode by movingsleeve 130 into a first or forward position where it obstructs piercingaperture 110 and a second or rearward position where sleeve 130 iswithdrawn from piercing aperture 110 so that sleeve 130 no longerimpinges on the user's skin when cap 108 is placed into contact with theuser prior to firing lancing device 102. Alternatively, sleeve 130 canprotrude forward past the skin contacting surface of cap 108. When thesleeve 130 is in its second or rearward position, for AST mode, it issufficiently spaced apart from the piercing aperture 110 so that it doesnot flatten the user's puckered skin during incision, as shown in FIG.33.

In other words, when the lancet sleeve 130 is interposed within thepiercing aperture 110, it adjusts the effective size of the piercingaperture 110 to a second diameter of the front end of the sleeve 150.When the lancet sleeve 130 is withdrawn from the piercing aperture 110,it adjusts the effective size of the piercing aperture to a larger firstdiameter, in this embodiment, the diameter of unobstructed piercingaperture 110. This larger first diameter is sufficiently large to allowthe user's skin to pucker into the piercing aperture 110, as shown inFIG. 33. Other mechanisms for changing the effective size of thepiercing aperture 110 and can be used as well. For example, the sleeve130 can be mounted to the housing 106, as opposed to the lancet 104, orthe skin engaging cap 108 can be deformed.

AST move actuator ring 116 is shown in more detail in FIGS. 35-37. ASTmode actuator ring 116 is a semi-circular body rotatably mounted inhousing 106 between shoulders 220 (FIG. 20). AST mode actuator ring 116includes left and right semi-circular portions 356 and 358 eachterminating in clasping ends 360 and 362, respectively. The diameter ofAST mode actuator ring 116 is sized to permit it to be secured aboutreceiver 170 as shown in FIG. 36 (with sectional view of receiver 170)when left and right semi-circular portions 356 and 358 are flexedslightly outward by the girth of receiver 170 to urge clasping ends 360and 362 into tight engagement of receiver 170.

AST mode actuator ring 116 includes two opposing bosses 364 and 366,each of left and right semi-circular portions 356 and 358, respectively.Each boss 364 and 366 is sized to engage corresponding cam trails 368and 370 on receiver 170 (see FIGS. 38 and 44), so that rotation of ASTmode actuator ring 116 will selectively position receiver 170 (and thuslancet sleeve) axially forward and axially rearward, depending on whichdirection AST mode actuator ring 116 is rotated. Receiver 170 isdisposed within housing 106 to allow axial (but not rotational)maneuvers.

As best seen in FIGS. 3, 18 and 36, a user-actuated member in the formof control member 372 extends from the AST mode actuator ring 116through AST mode actuator aperture 202 in the housing 106 to provide auser interface for manipulation of AST mode actuator ring 116 by theuser. The user has adjusted the effective size of the piercing aperture110 to the chosen diameter when a portion of the AST mode actuator ring116 is positioned in visual association with the indicia. Becausecontrol member 372 is captured in AST mode actuator aperture 202, thesize of AST mode actuator aperture 202 defines the range that the usercan rotate AST mode actuator ring 116. Other user interfaces can beemployed, including textured gripping surfaces. AST mode actuatoraperture 202 is forms a slot having lateral ends that define a path oftravel there between for control member 372. The shape of aperture 202may be varied to ovoid, rectilinear or other suitable shapes.

Indicia 376 on the outer circumferential surface of the AST modeactuator ring 116 is visible to the user through AST mode actuatoraperture 202 when AST mode actuator ring 116 has been rotated to theswitch lancing device 102 into AST mode. In this case, indicia 376 is adiagram of a human body, conveying to the user the fact that in AST modelancing device 102 can be used to draw bodily fluid from tissue otherthan a finger, other symbols or icons may be used. Alternatively,indicia 376 can be located on AST mode actuator ring 116 so that indicia376 is visible through AST mode actuator aperture 202 when AST modeactuator ring 116 has been rotated to switch lancing device 102 intofinger mode. Alternatively, two indicia can be used, one to indicate ASTmode and the other to indicate finger mode. Alternatively, the twoindicia may be located on the housing.

Referring to FIGS. 38 through 44, receiver 170 is described. Asexplained below, receiver 170 acts as a sleeve-engagement portion toreleasably engage lancet sleeve 130. Receiver 170 is coupled to AST modeactuator ring 116 and configured to move sleeve 130 in response to themovement of AST mode actuator ring 116. Receiver 170 is generallytubular in construction with a cylindrical receiver body 380 defining anelongated inner chamber 381 therein that is sized and configured toreceive lancet 104 as shown in FIG. 40. Elongated slot 222 runs thelongitudinal extent of the underside of receiver 170.

Referring to FIG. 38, cam trails 368 and 370 are cut into the left andright exterior sides of receiver body 380. Cam trail 368 on the leftside of receiver body 380 runs at a 45 degree angle from vertical from aforward-upper portion of the left exterior side of receiver body 380 toa lower-rearward portion of the left exterior side of receiver body 380.The angle determines the ratio of angular rotation to linear translationand can be varied to achieve different amounts of translation.

Cam trail 370 is complementary to cam trail 368, and runs at a fortyfive degree angle from vertical from a forward-lower portion of theright exterior side of receiver body 380 to a upper-rearward portion ofthe right exterior side of receiver body 380.

AST mode actuator is clasped about receiver body 380 of receiver 170 sothat bosses 364 and 366 are inserted into cam trails 368 and 370,respectively, as shown in FIG. 36. As AST mode actuator ring 116 rotatesrightward (that is, clockwise when looking at AST mode actuator ringfrom the rear of lancing device 102), bosses 364 and 366 drive receiver170 (and thus lancet sleeve 130) axially rearward to the AST modeposition (FIG. 33). As AST mode actuator ring 116 rotates leftward (thatis, counter-clockwise when looking at AST mode actuator ring from therear of lancing device 102), bosses 364 and 366 drive receiver 170 (andthus lancet sleeve 130) axially rearward to the finger mode position(see FIG. 34). Lancet body 122 is engaged by lancet carrier 208, so thatlancet body 122 does not move as receiver 170 axially slides lancetsleeve 130.

Extending from the forward end of receiver body 380 are a pair of upperend lower guide fins 382 and 384 and a pair of lateral fins 386 and 388.Lower guide fine 384 is longitudinally bifurcated by slot 222. Fins382-388 are curved about their respective longitudinal axii to define aportion of the circumference of a circle about the major axis ofreceiver body 380, as most readily seen in the front view of FIG. 42.

When lancet 104 is fully inserted into receiver 170, sleeve 130 isdisposed in the closure defined by upper and lower guide fins 382, 384and lateral fins 386, 388, with the rear end 152 of sleeve 130 abuttinga backstop 389 (FIG. 39) formed in the elongated interior chamber 381 ofreceiver 170 and in the sectional view of FIG. 18. In thisconfiguration, lancet body 122 extends entirely through the elongatedinterior chamber 381 so that conical rear end 136 of lancet body 122extends from the rear end of receiver 170 and is engaged by lancetcarrier 208.

Reinforcements 390, at the rear end of upper and lower guide fins 382and 384, provide rigidity to guide fins 382 and 384 and to align thereceiver within the housing. Lateral fins 386 and 388 do not havereinforcements and are sufficiently thin so as to have flexibility inresponse to lateral forces.

The front tips of lateral fins 386 and 388 include opposing inwardlyprojecting snaps 392. When lateral fins 386 and 388 are in a relaxedstate (that is, not flexed outward), the distance between snaps 392 isslightly less than the diameter of annular flange 164 of sleeve 130. Aslancet 104 is inserted into receiver 170, annular flange 164 abuts snaps392. Continued insertion of annular flange 164 against snaps 392 willflex lateral fins 386 and 388 slightly apart, permitting passage ofannular flange 164 into elongated interior chamber 381. Once annularflange 164 is clear of snaps 392, lateral fins 386 and 388 (having beenpushed apart) urge snaps 392 into clasping engagement with mountingshoulder 166 on the front side of annular flange 164, as best seen inFIG. 18. Other suitable means can be used to couple receiver 170 andlancet sleeve 130.

Elongated interior chamber 381 is configured for mating engagement withthe external contours of lancet sleeve 130 and lancet body 122. As shownin the cut-away perspective view of FIG. 39, receiver body 380 includesa forward internal portion 400 and a rearward internal portion 402.

Forward internal portion 400 of receiver body 380 has a diametersufficiently wide to accommodate the rear portion 158 of sleeve 130.Forward internal portion 400 forms lateral guide wall 404 a which has avertical planar face and upper guide wall 40 b which has a horizontalplanar face forming a 90° intersection 405 with guide wall 404 a in theupper right-hand portion of elongated interior chamber 381. FIG. 42 is afront view of receiver 170 showing in phantom lines a sectional view oflancet sleeve 130. When lancet sleeve 130 is inserted into receiver 170,depending on the random orientation of lancet 104 in the user's handwhen inserted into lancing device 102), one of either planar surface 172c or 172 f (see FIG. 15) will be flush against guide wall 404 a, and theadjacent planar surface 172 d or 172 a (again, depending on theorientation of lancet 104 when inserted into lancing device 102) will beflush against guide wall 404 b, so that the intersection of planarsurfaces 172 c and 172 d (or, as the ease may be, 172 f and 172 a) willbe aligned in mating engagement with intersection 405, as shown in FIG.42. A pair of guide walls 404 c and 404 d can be provided in the lowerleft-hand portion of elongated chamber 381 to engage the pair of planarsurfaces 172 that are opposite the pair of planar surfaces engaged byguide walls 404 a and 404 b. It will be seen in FIG. 42 that theengagement of one of planar surfaces 172 with walls 404 will rotate theentire lancet forty five degrees from vertical orientation.

As seen in FIGS. 39 and 41, rearward internal portion 402 of receiverbody 380 has a diamond-shaped cross section sized to accommodate lancetbody 122 and including rear guidewalls 408. Rearward internal portion402 is narrower than forward internal portion 400.

When lancet 104 is initially inserted into receiver 170 by the user,sleeve 130 is in its extended protective position and locking memberwings 132 a, 132 b are in the extended configuration to engage sleeve130 and prevent sleeve 130 from sliding toward the rear end of lancetbody 122 (as shown in FIG. 5).

During insertion of the lancet 104 into receiver 170, the rear half oflancet body slides readily through the rearward internal portion 402 ofreceiver. As wings 132 a, 132 b enter rearward internal portion 402,they are folded into wing wells 142 a, 142 b by the constricted widthbetween guide walls 408 into the retracted configuration, as best seenin FIG. 41.

When lancet 104 is fully inserted into lancing device 102, sleeve 130 issecured to receiver 170 by snaps 392 (at sleeve's front end 150) andbackstop 389 (at sleeve's rear end 152). Thus, axial movement ofreceiver 170 will cause sleeve 130 to slide axially relative to piercingaperture 110 from its finger mode position (shown in FIGS. 31 and 33) toits AST mode position (shown in FIGS. 32 and 34) while lancet body 122(and needle 118 embedded therein) remain in place relative to piercingaperture 110. At the same time, lancet body 122 is engaged in the mouth260 of lancet carrier 208, so that lancet body 122 does not move axiallyas receiver slides sleeve 130 forward and rearward, as can be seen bycomparing the position of lancet body 122 in FIGS. 33 and 34.

When lancet sleeve 130 is fully inserted into receiver 170, rear end 152of sleeve 130 will impinge on backstop 389 of receiver 170, so thatlancet sleeve 130 (and consequently, lancet body 122), cannot be furtherinserted. Thus, firm insertion of lancet 104 when lancing device 102 isin AST mode will cause conical rear end 136 of lancet body 122 to drivelancet carrier 208 rearward into its cocked position shown in FIG. 30 c.Note that after initial firing, lancing device can be re-cocked bypulling cocking handle as described above in reference to FIG. 30 b.

It will be seen that AST mode actuator ring 116 and receiver 170function together as an actuator that releasably engages sleeve 130 topermit the user to selectively move sleeve 130 relative to housing 106and lancet needle 118. Other mechanisms can be employed within the scopeof the present invention to accomplish this function. For example,referring to FIGS. 48 and 49, in lieu of rotatable AST mode actuatorring 116, a linear switch 460 can be provided which includes a finger470 extending though a slot 480 in cap 108. Slot 480 can be parallel tothe longitudinal axis of housing 106, and finger 470 can be coupled tothe receiver so that axial movement of finger 470 by the user drivescorresponding axial movement of sleeve 130. Also, in lieu of receiver170, different structures may be employed to releasably clasp sleeve130. For example, the end of finger 470 can include a pair of tines 490to clasp sleeve 130 about annular flange 164, thus translating axialmovement of finger 470 to corresponding axial movement of sleeve 130.Alternatively, inner chamber 381 of receiver 170 can be sized to holdsleeve 130 in a friction fit.

It should also be noted that while AST mode actuator ring 116 andreceiver are directly coupled together, they may also be effectivelycoupled for purposes of the invention through one or more intermediateparts.

Ejection Slide and Ejection Actuator

Referring to FIGS. 45 and 46 a through 46 d, the structure and operationof ejection slide 115 and ejection actuator 121 is discussed. Ejectionslide 115 is a user actuated feature external to housing 106, whosefunction (in conjunction with ejection actuator 121) is to eject lancet104 from lancing device 102 such as after use.

Ejection actuator 121 is slidably mounted within housing 106 andincludes an elongated main body 420 having top surface 422. A finger 424extends from top surface 422 near the front end of main body 420 intothe underside of receiver 170 through elongated slot 222, where finger424 is to the rear of and the same height as the down most portion ofejection shoulder 168, as best shown in FIG. 18. Alternatively, finger424 can engage another part of sleeve 130, such as its rear end 152. Asexplained below, finger 424 engages lancet sleeve to eject lancet 104from lancing device 102. Two tongues 426 extend laterally and inopposing directions from the underside of main body 420. Each of tongues426 extends through its adjacent one of elongated slots 240 formed inlateral walls of housing 106, permitting ejection actuator 121 to slidealong elongated slots 240 in forward and rearward axial directions, butotherwise preventing lateral or vertical movement of ejection actuator121.

Tongues 426 projects through slots 240 and are received by wells 430formed on the interior side of ejection slide 115. tongues 426 can beaffixed in wells 430 by means of adhesive, snap engagement or othersuitable means. Thus, ejection slide 115 is coupled to ejection actuator121 so movement of one will cause movement of the other.

During lancing operations, ejection slide 115 and ejection actuator 1121are in their rearmost at rest positions. To eject lancet 104, the userslides ejection slide 115 forward toward piercing aperture 110 from itsat rest position. This in turn causes ejection actuator 121 to slidewithin housing, engaging and ejecting lancet 104 as described below. Aspring or other biasing device (not shown) can be provided to biasejection slide 115 and ejection actuator 121 in their most rearwardposition so as to avoid unintended ejection of lancet 104.

Ejection actuator 121 operates in conjunction with a locking member 432,which is disposed between top surface of main body 420 and lower jaw 264of lancet carrier 208. The function of locking member 432 is to restrainthe release of the lancet body 122 from the upper and lower jaws 262,264 of the lancet carrier 208 until the lancet sleeve 130 has been fullyextended by the ejection actuator 121.

Locking member 432 has an elongated body 434 having an upper surface 436and a lower surface 438. Near its front end 440, elongated body 434forms an upwardly facing bar 442 and a downwardly facing convex surface444. At its rear end, elongated body 434 is pivotally mounted to lancetcarrier 208 by pivot 446, so as elongated body 434 rotates about thispivot, its front end 440 is raised and lowered relative to the lower jaw264 of lancet carrier 208.

Locking member 432 is aligned in parallel superposition with ejectionactuator 121 so that locking member 432 rests on a top surface 422 ofejection actuator 121. Top surface 422 includes an upwardly-facingconcave recess 450 sized and shaped to hold the downwardly facing convexsurface 444 of locking member 432. When ejection actuator 121 is in itsmost rearward position, convex surface 444 is aligned with and rests inconcave recess 450. In this position, bar 442 is clear of lower jaw 264.

FIGS. 46 a through 46 d illustrate the operation of the ejection slide115 and ejection actuator 121. After insertion of lancet 104 andoperation of lancing device 102, ejection slide 115 and ejectionactuator 121 are in their rearmost at rest positions, as shown in FIG.46 a. To eject lancet 104, the user slides ejection slide 115 forwardtoward piercing aperture 110. The resulting sliding motion of ejectionactuator 121 causes finger 424 to move forward through slot 222 inreceiver 170.

Referring to FIG. 46 b, as ejection actuator slides 115 slides forward,convex surface 444 of locking member 432 slides out of concave recess450 and onto top surface 422 of ejection actuator 121. As a result, bar442 is thrust upward so that it engages with the underside of lower jaw264 forcing lower jaw 264 to remain clamped about neck 138 of lancetbody 122. It will be appreciated that in order for sleeve 130 to slideinto the desired extended position (thus protecting sharp tip 120), itis helpful that lancet body 122 and lancet carrier 208 remainstationary. However, as lancet sleeve 130 moves forward, it may exert aforce on lancet body 122 due to friction as the sleeve 130 slidesaxially over lancet body 122. This force has the tendency to pull lancetbody 122 out of lancet carrier 208 and along with sleeve 130, thuspreventing sleeve 130 from fully extending relative to lancet body 122.Even if lancet body 122 remains engaged by lancet carrier 208, theforward thrust on lancet 104 may move lancet carrier 208 forward.Locking member 432 restrains the release of the lancet body 122 from theupper and lower jaws 262, 264, thus holding lancet body stationary whilelancet sleeve is pushed forward by finger 424. At the same time, itblocks forward movement of lancet carrier 208.

As the user continues to slide ejector 115 forward, finger 424 movesthrough the slot 222 in the receiver 170, until it engages ejectionshoulder 168 formed in an annular flange 164 of the lancet sleeve 130(see also FIG. 10 for more detailed view of ejection shoulder 168).Continued forward movement of the ejection actuator 121 causes finger424 to slide lancet sleeve 130 axially over lancet body 122 in forwarddirection so that sleeve 130 surrounds sharp tip 120 in the extendedprotective position.

Referring to FIG. 46 c, when ejection actuator 121 has pushed sleeve 130to its most forward position relative to lancet body 122, guide ribs 134of lancet body 122 engage backstops 182 at the end of grooves 180 insidethe inner chamber 154 of sleeve 130. Further movement of sleeve 130 byejection actuator 121 requires that lancet body 122 be pulled out ofjaws 262, 264 of lancet carrier 208. At this time point in the forwardtravel of ejection actuator 121, the convex surface 444 locking member432 has reached the end of top surface 422 and drops off the rear end ofejection actuator 121. This action allows bar 442 to fall below thelower jaw 264 and permits lower jaw 264 to be opened in response tourging of lancet body 122.

Referring to FIG. 46 d, as continued movement of ejection actuator 121pushes lancet sleeve 130 and lancet body 122 forward, wings 132 a, 132 bon lancet body 122 slide from the rearward internal portion 402 to theforward internal portion 400 of receiver 170. In the wider forwardinternal portion 400, wings 132 a, 132 b (which had been folded intowing wells 142 a, 142 b) are no longer deformed and restrained by rearguide walls 408 of receiver 170, and accordingly wings 132 a, 132 b flapout into an extended V-shaped configuration (See FIG. 5). In thisextended V-shaped configuration, wings 132 a, 132 b engage and preventsleeve 130 from moving axially rearward and thus exposing sharp tip 120.

With ejection slide 121 moved to its full forward position, finger 424has pushed sleeve 130 so that its front portion 156 protrudes throughpiercing aperture 110 of cap 108. The user may now engage the protrudingfront portion 156 to pull lancet 104 out of the lancing device 102.Because the sleeve 130 has been extended to surround needle's sharp tip,it is less likely that the user will prick himself or herself ingrasping the lancet 104 for removal. Lancet 104 may also be dropped outof lancing device 102 without the user touching lancet 104 at all.

FIGS. 47 a and 47 b show another embodiment of lancing device 102, whichincludes a skin-engaging cap 500 with additional features for improvingthe user's comfort, expressing blood from the site of a lancing incisionand stabilizing the device on the skin. Cap 500 includes a piercingaperture 502, which in this case may be elongated with a enlarged centerportion 504. Cap 500 has a rigid base 506 which can be opaque, and askin-engaging cover 508 which is composed of electrometric material andcan be transparent. A plurality of small bumps 510 are disposed aboutthe piercing aperture 502 and are mounted on upwardly extending arms 512which act as cantilevers. Arms 512 can be mounted to ridged base 506 andcan extend upward at an angle (as shown) through the electrometric cover508 so that a portion of arms 512 extends beyond the cover.

Arms 512 are flexible to permit bumps 510 to move toward cap 500 whenbumps 510 are pressed against the user's skin. When bumps 510 movetoward cap 500, they draw closer to the piercing aperture 502,concentrating blood near the incision. Electrometric cover 508 serves toadd compliance to the skin as well as to spread the motion of bumps 510to adjacent skin. Arms 512 can include stops or other suitablemechanisms (not shown) to limit inward movement of bumps 510. Thispermits lancing depth to be more predictable and less dependant upon theforce applied to the user's skin.

Additional Embodiment for Depth Adjustment

Referring to FIGS. 50 a and 50 b, an alternative embodiment isillustrated for adjusting penetration depth of sharp tip 120. In thisembodiment, sleeve 130 slides through the front end of the cap 108 bythe motion of AST mode actuator ring 116 and receiver 170, as describedabove. However, cam trails 368 and 370 of receiver 170 are cut to permitreceiver 170 to move a greater distance toward cap 108 when AST modeactuator ring 116 is rotated. In this manner, the front end 150 ofsleeve 130 can be extended through the piercing aperture 110 to providea skin engaging surface 514 that protrudes from the plane of piercingaperture 110 by a distance “d” as shown in FIG. 50 b.

Because sleeve 150 extends beyond piercing aperture 110, it spaces theuser's finger away from needle 118 and reduces by the distance “d” thelength of sharp tip 120 that is exposed to penetrate the user's skin.The farther out sleeve 130 is extended, the less distance sharp tip 120penetrates the user's skin.

Referring to FIGS. 50 a and 50 b, sleeve 130 is held by receiver 170,which in turn is controlled in cam-like fashion by AST mode actuatorring 116. To adjust the position of sleeve 130 relative to piercingaperture 110, the user rotates AST mode actuator ring 116, which drivesthe receiver 170 (and hence the lancet sleeve 130) axially toward oraway from the skin-engaging surface 254 of the cap 108 (depending onwhich direction the user rotates AST mode actuator ring 116). It will beseen that actuator ring 116 can operate as a user-operable switch orcontrol to adjust penetration depth by moving sleeve 130 into a firstposition where it extends beyond piercing aperture 110 and a secondposition (see for example FIG. 33) where sleeve 130 is withdrawn frompiercing aperture 110 so that sleeve 130 no longer impinges on theuser's skin when cap 108 is placed into contact with the user prior tofiring lancing device 102. AST mode actuator ring can also be rotated toa third position, for example, where sleeve 130 extends beyond piercingapertures 110 by a distance less than or greater than distance d. Byselectively position AST mode actuator ring, the user can achieve adesired depth penetration level. Detents and indicia can be provided onAST mode actuator ring 116 to assist users in selecting a desiredposition.

Additional Embodiment of Lancing Device

Referring to FIG. 51, alternative embodiment of lancing system 100includes a lancing device 102′ and a lancet such as lancet 104. Lancingdevice 102′ is similar in construction and operation to lancing device102, and only those features that are different are described in detail.Lancing device 102′ is operated by a user to draw a sample of blood orother bodily fluid from the body such as for diagnostic purposes.Lancing device 102′ includes a housing 106′ with a skin-engaging cap108′ having a piercing aperture 110′ and a cocking handle 112′ used tocock an internal firing mechanism (described below). Cocking handle 112′includes an elongated rod 314′ extending into the interior of housing106′ that terminates in an L-shaped cocking hood 316′.

Lancing device also includes a trigger assembly 515 that includes atrigger button 523 that projects through a trigger aperture 203′ inhousing 106′. An ejection slide 519 is provided to eject lancet 104 fromlancing device 102′ after use. Housing 106′ includes right- and lefthalf portions, 204′ and 206′, respectively.

An AST mode actuator ring 116′ is provided which operates with areceiver 170′ substantially as described above with respect to actuatorring 116 and receiver 170.

A carriage assembly 517 is disposed within housing 106′ for slidingaxial movement to and away from piercing aperture 110′. Included incarriage assembly 517 is a slidable lancet carrier 208′ that engageslancet 104, a drive spring 210′ that propels the lancet carrier 208′toward piercing aperture 110′ to drive lancet 104 to pierce the user'sskin or other bodily tissue. Also included with in carriage assembly 517is a return spring 212′ that propels lancet carrier 208′ rearward towithdraw lancet 104 from the user's skin after piercing. If desired,lancing device 102′ can be equipped with other drive mechanisms, such asa coil spring, a leaf spring, and electromechanical or electromagnetdrive or other suitable mechanisms known in the art to propel lancetcarrier 208′ axially within housing 106′.

Lancing device 102′ includes a depth adjuster 521 which operates inconcert with carriage assembly 517. As explained below, the user'srotation of depth adjuster 521 causes carriage assembly 517 to slideaxially within the housing 106′ to regulate penetration depth of lancet104 when lancing device 102′ is fired.

Ejection Slide and Ejection Actuator

Referring to FIGS. 52 and 53, the structure and operation of an ejectionactuator 516 and an ejection slide 519 (shown in FIG. 51), whosestructure and operation are substantially the same as ejection actuator121 and ejection slide 115 discussed above.

Ejection actuator 516 is slidably mounted within housing 106′ andincludes an elongated main body 518 with a spine 520 extending upwardlytherefrom along the longitudinal extend of the main body. Spine 520includes a finger 522 whose structure and function is the same as thatof finger 424 described above. Ejection actuator 516 operates inconjunction with a locking member 524 (which is used in place of thelocking member 432 described in the previous embodiments).

To eject lancet 104 (not shown in FIGS. 52 and 53), the user slidesejection slide (not shown in FIGS. 52 and 53) forward toward piercingaperture 110′. This in turn causes ejection actuator 516 to slide withinhousing, engaging and ejecting lancet 104 as described above inreference to FIGS. 45-46. Ejection actuator 516 operates in conjunctionwith a locking member 524 to restrain movement of lancet carrier 208′during operation of ejection actuator 516 as described below.

Referring to FIGS. 54-59, locking member 524 is described. Lockingmember 524 includes a cylinder 526 from which extend upper arm 528 andlower arm 530. Upper arm 528 defines an abutment surface 532 near itsdistal tip. Lower arm 530 defines a front surface 534 and a rear surface536 near it distal end.

Referring to FIG. 52 a, cylinder 526 is mounted to housing to permitrotation about its major axis. Lower arm 530 extends from cylinder 526so that its distal end extends into a notch 538 in spine 520 of ejectionactuator 516 when ejection actuator is at its rearward “at-rest”position. Notch 538 defines a front wall 540 and rear wall 542 as bestseen in FIGS. 52 b and 53 b. In this “open” configuration, upper arm 528is clear of an engagement boss 280′ on lancet carrier 208′, as shown inthe top plan view of FIG. 53 a. Accordingly, locking member 524 does notin this configuration prevent forward axial movement of lancet carrier208′.

As ejection actuator 516 slides forward (in the direction of arrow A inFIGS. 52 a and 53 a), rear wall 542 of notch 538 impinges on rearsurface 536 of lower arm 530, driving lower arm 530 away from thecentral axis of lancing device 102′ and causing locking member 524 topivot about cylindrical main body 526 in clockwise direction D (FIG. 53b) to swing upper arm 528 to a position adjacent to a front of drivespring engagement boss 280′ on lancet carrier 208′, as shown in FIGS. 52b and 53 b. In this “closed” configuration, the abutment surface 532 ofupper arm 528 abuts drive spring engagement boss 280′ in blockingengagement to block forward movement of lancet carrier 208′, as bestseen in FIG. 53 b.

As with the embodiments of FIGS. 45-46, ejection actuator 516 engagessleeve 130 to eject lancet 104. As ejection actuator 516 pushes sleeveforward to its extended position, lancet body 122 is held by lancetcarrier 208′ by a pair of jaws similar in construction to jaws 262 and264 described above. As lancet sleeve 130 moves forward, it may exert aforce on lancet body 122 due to friction as the sleeve 130 slidesaxially over lancet body 122. This force has the tendency to pull lancetbody 122 out of lancet carrier 208′ and along with sleeve 130, thuspreventing sleeve 130 from fully extending relative to lancet body 122.The snap closure of jaws on lancet carrier 208′ may be sufficientlystiff to prevent removal of lancet body 122 as lancet sleeve 130 ispushed forward. However, the thrust imposed on lancet body 122 iscommunicated to lancet carrier 208′, which then has a tendency to move.In the closed position, as shown in FIGS. 52 b and 53 b, locking member524 engages a boss 280′ extending from lancet carrier 208′ to preventforward movement of lancet carrier 208′. As ejection actuator 516continues to move forward, the distal end of lower arm 530 is thrust outof notch 538 and abuts a sidewall 544 of spine 520, which preventsrotation of locking member to its open position shown in FIG. 52 a.

After lancet 104 is ejected, ejection actuator 516 returns rearward toits at-rest position as shown in FIGS. 52 a and 53 a. As ejectionactuator 516 returns to its rearward at-rest position, from wall 540pushes lower arm 530 rearward, pivoting locking member 524 about itscylindrical body 526 into the open configuration shown in FIGS. 52 a and53 a.

It will appreciated that that when locking member 524 is in its closedconfiguration, substantially all of the force exerted on locking member524 by lancet carrier 208′ is transmitted to housing 106′ via maincylindrical body 526, whose interface with housing 106′ acts as abearing surface, which is static while locking member 524 is in itsclosed configuration. Other bearing surfaces can be provided as well(apart from ejection actuator 516) and substantially all of the forceexerted by lancet carrier 208′ can be distributed amongst these bearingsurfaces in any desired proportion.

Additionally, the forward thrust of lancet carrier 206′ upon upper arm528 urges locking member 524 to continue rotating in a clockwisedirection of arrow D (as shown in FIG. 53 b) urges upper arm 528. Thiscan reduce or eliminate the force directed onto ejection actuator 516via lower arm 530, which in turn reduces the friction between lower arm530 of locking member 524 and sidewall 544 of ejection actuator 516, asejection actuator 516 moves forward past lower arm 530.

Referring to FIG. 53 b, it will be seen that the forward thrust oflancet carrier 206′ urges locking member 524 to rotate in the clockwisedirection of arrow D because the upper arm 528 has rotated sufficientlyfar in the clockwise direction about cylinder 526.

As alternative embodiment in the form of ejection actuator 516′ andlocking member 524′ is illustrated in FIGS. 59A and 59B. Ejectionactuator 516′ and locking member 524′ operate substantially as describedabove with respect to ejection actuator 516 and locking member 524.Ejection actuator 516′ is slidably mounted within housing 106′ andincludes an elongated main body 518′. Locking member 524′ includes acylinder 526′ from which extend upper arm 528′ and lower arm 530′. Upperarm 528′ defines an abutment surface 532′ near its distal tip. Lower arm530′ defines a front surface 534′ and a rear surface 536′ near it distalend.

Lower arm 530′ extends from cylinder 526′ so that its distal end extendsinto a notch 538′ in elongated main body 518′. Notch 538′ defines afront wall 540′ and rear wall 542′ as best seen in FIG. 59B. Tofacilitate the rotation of lower arm 530′ about cylinder 526′ whenengagement actuator 516′ moves forward, rear wall 542′ and rear surface536′ have corresponding convex contoured surfaces.

Referring to FIG. 59A, lancet carrier 208′ includes a projection 545jutting forward to engage abutment surface 532′ of upper arm 528′. Theforward end of projection 545 includes a beveled front face 546 thatdefines a V-shaped contour. Abutment surface 532′ is tapered to engageface 546 so that forward movement of lancet carrier 208′ urges lockingmember 524′ to rotate about cylinder 526′ in the direction of arrow E.This can reduce or eliminate the force directed onto ejection actuator516′ via lower arm 530′, which in turn reduces the friction betweenlower arm 530′ of locking member 524′ and sidewall 544 of ejectionactuator 516′, as ejection actuator 516′ moves forward past lower arm530′.

If desired, a bias element such as a spring can be included to also urgelocking member 524′ to rotate in the direction of arrow E.

Referring to FIG. 59C, another embodiment is illustrated in the form oflocking member 547. Locking member 547 is mounted to housing 106′ (notshown in FIG. 59C) by guide tracks 549 a, 549 b to permit locking member547 to slide laterally in the direction of arrow F between a position(as shown in FIG. 59C) where locking member 547 does not block theforward movement of lancet carrier 208′ and a position where lockingmember 547 does block the forward movement of lancet carrier 208′ (asshown in FIG. 59D). Locking member 547 is coupled to ejection actuator516″ by a rod 548 that is pivotally mounted to both locking member 547and ejection actuator 516″. As ejection actuator 516″ moves forward inthe direction of arrow G during ejection, rod 548 urges locking member547 away from ejection actuator 516″ and into blocking engagement withlancet carrier 208′. It will be noted that when locking member 547 isblocking the forward movement of lancet carrier 208′, substantially allof the forward force imposed by lancet carrier 208′ can be borne by thebearing surfaces of guide tracks 549 a, 549 b, which can be close enoughto locking member 547 an lancet carrier 208′ to reduce or eliminatetorque imposed on rod 548.

Lancet Interlock

Referring to FIGS. 60 through 71, an interlock member 554 isillustrated. Interlock member 554 prevents lancet 104 (shown in FIG. 61c) from being inserted for operable engagement into lancing device 102′when lancing device 102′ is cocked. The interlock member selectivelyprevents the lancet from being operably engaged for use. This featurereduces the chance that a user will accidentally prick himself orherself while loading lancet 104 into lancing device 102′.

Interlock member 554 cooperates with a trigger assembly 515. Withrespect to the cocking and firing operations of lancing device 102,trigger assembly 515 operates in substantially the same manner astrigger 114 shown in FIGS. 27-30. When lancing device 102′ is cocked,trigger assembly 515 pivots in see-saw fashion so that trigger button523 moves upward to extend through a trigger aperture 203′ of housing106′ (shown in phantom lines in FIGS. 60 and 61). When lancing device102′ is uncocked, trigger assembly 515 pivots in see-saw fashion so thattrigger button 523 moves downward.

As explained below, trigger button 523 is coupled to interlock member554 so that when lancing device 102′ is cocked, the resulting upwardmovement of trigger button 523 causes interlock member 554 to swing toan engagement position (shown in FIGS. 60 b and 61 b) in which interlockmember 554 blocks or is interposed into the path of insertion P oflancet 104 to prevent full insertion of lancet 104 into lancing device102′. When lancing device 102′ is not cocked, the resulting downwardmovement of trigger button 523 causes interlock member 554 to swing to adisengagement position (shown in FIGS. 60 a and 61 a) in which interlockmember 554 does not prevent the insertion of lancet 104 into lancingdevice 102′.

Referring to FIGS. 62 through 69, interlock member 554 is illustrated.Interlock member 554 includes an elongated main body 556 having ablocking member 558 as its front end and an elongated cylinder 560 atits rear end. The major axis of cylinder 560 is generally perpendicularto the major axis of main body 556. Cylinder 560 is mounted to housing106′ to permit cylinder 560 to rotate about its major axis. As cylinder560 rotates, interlock member 554 swings into and out of its engagementand disengagement positions.

A resilient cantilever spring 562 extends from an off-center rearportion of cylinder 560 and terminates in a distal portion 563 that isspaced apart from main body 556. Distal portion 563 of cantilever spring562 engages housing 106′ in a position that flexes cantilever spring 562and urges interlock member 554 to rotate about the major axis ofcylinder 560 to move blocking member 558 to its engagement position inwhich at least a portion of the blocking member 558 is interposedbetween the front end of the housing 106′ and the lancet holdingassembly to block full insertion of the lancet 104 into the housing 106′by blocking the path of insertion P of lancet 104 (see FIG. 61 b).

As best seen in FIGS. 62-63 and 68-69, blocking member 558 includes twofront-facing surfaces 564 and 565. Surfaces 564 and 565 form an angletherebetween of about 120 degrees; however, other angles andconfigurations can be selected.

A cam follower 566 extends upward from main body 556. As best seen inFIG. 64, cam follower 566 includes a vertical base portion 568 andhorizontal finger portion 570 extending from the upper end of verticalbase portion 568. Finger portion 570 is crowned by a boss 572.

Referring to FIGS. 60 a, 70 and 71, the interaction of trigger button523 and interlock member 554 determines the position of interlock member554 when lancet 104 is not inserted into lancing device 102′. Interlockmember 554 is disposed within housing 106′ adjacent to the triggerbutton 523. Trigger button 523 includes a cam trail 574 positioned toadmit finger 570 of cam follower 566, as best seen in FIGS. 70 and 71.Inside of cam trail 574 is a sloped cam surface 576, against which boss572 engages under the bias force of cantilever spring 562.

Because of the slope of cam surface 576, upward movement of triggerbutton 523 will permit finger 570 to move (under the bias force ofcantilever spring 562) in the direction of arrow “C” toward the path ofinsertion P (see FIGS. 61 b and 71). As finger 570 moves in thedirection of arrow “C”, interlock mechanism 554 rotates clockwise aboutcylinder 560 (when viewed from above), thus swinging blocking member 558into an engagement position where it blocks the path of insertion P oflancet 104 (see FIG. 61 b).

Likewise, downward movement of trigger button 523 will force finger 570to move in the direction of arrow “D” away from the path of insertion P(see FIG. 61 a) of lancet 104. As finger 570 moves in the direction ofarrow “D”, finger 570 overcomes the bias force of cantilever spring 562to drive interlock mechanism 554 to rotate counter-clockwise (whenviewed from above) about cylinder 560, thus swinging blocking member 558into an disengagement position where it does not block the path ofinsertion P (see FIG. 61 a).

Referring to FIGS. 61 a through 61 c, operation of trigger button 523(shown in phantom lines) and interlock member 554 is illustrated. Asshown in FIG. 61 a, when lancing device 102′ is uncocked, trigger button523 is in a lowered elevation, forcing rotation of interlocking member554 to the disengagement position. The user may insert lancet 104 intolancing device. As shown in FIG. 61 b, when lancing device is cocked,such as by pulling cocking handle 112′, trigger button 523 is in anelevated position, forcing rotation of interlocking member 554 to theengagement position where blocking member 558 obstructs the path ofinsertion P for inserting a lancet 104. When interlocking member 554 isin the engagement position, the user cannot fully insert lancet 104 intolancing device 102′.

As shown in FIG. 61 c, if lancet 104 is inserted into lancing device102′ when lancing device is uncocked, and then subsequently lancetdevice is cocked, the resulting elevation of trigger button 523 wouldpermit interlock member 554 to swing into its engagement positionblocking path of insertion P of lancet 104. However, with lancet 104already inserted (as shown in FIG. 61 c), blocking member 558 simplyabuts the side of lancet body 122.

It will be appreciated that the lancet interlock detailed above may beany other suitable interlock means, including for example slidablelocking means or push tab locking means. It will be further appreciatedthat the movement of interlock member 554 may be actuated by othersuitable arrangement and references to such arrangements are not limitedto trigger button 523. For example, lancet carrier 208 can be coupled bycam action to interlock member 554 to urge interlock member 554 out ofpath of insertion P when lancet carrier 208 is moved out of its cockedposition.

Carriage Assembly

Referring to FIGS. 51 and 72, the structure and operation of carriageassembly 517 is described. Carriage assembly includes a carriage 580 anda carriage cover 582 suitably connected together to define therebetweena chamber 584 in which lancet carrier 208′ is captured as seen in FIG.73. Opposing top and bottom portions of lancet carrier 208′ engagesplanar guide surfaces 586 of carriage 580 to permit lancet carrier 208′to slide axially within carriage assembly 517, as seen in FIG. 73. FIGS.74 and 75 show carriage 580 in more detail. FIG. 77 shows carriage cover582 in more detail. Carriage 580 and carriage cover 582 can be connectedin any suitable manner, such as by snaps 558 on carriage cover 582.Adhesive, screws or other suitable fasteners may also be used.

As seen in FIGS. 72 and 73, carriage 580 includes a boss 590 on whichdrive spring 210′ is mounted and a boss 592 on which drive spring 212′is mounted. Springs 210′ and 212′ engage lancet carrier 208′ to movelancet carrier 208′ to and away from piercing aperture in the samemanner as described above with respect to springs 210 and 212 and lancet208. When a user pulls cocking handle 112′, rod 314′ draws back cockinghook 316′ which engages lancet carrier 208′ to pull lancet carriertoward the rear of housing 106′ and thus tensioning drive spring 210′.When trigger assembly 515 is actuated, lancet carrier 208′ is releasedfrom this tensioned or cocked position and is propelled forward to drivelancet 104 forward toward the piercing aperture 110′ and thus penetratesthe user's skin. As lancet carrier 208′ moves forward in a piercingaction, it engages and tensions return spring 212′, which then impelslancet carrier 208′ toward the rear of housing 106′, thus retractinglancet 104 from the user's skin. The operations of springs 210′ and 212′and the lancet carrier 208′ and cocking handle 112′ are substantiallythe same as described above with respect to springs 210 and 212 andlancet carrier 208 and cocking handle 112.

When lancet carrier 208′ is fired, its forward motion is limited by afixed projection such as a stop 593 located on carriage 580. Projectionor stop 593 is fixed and is not aligned with or otherwise moved relativeto lancet carrier 208′. Thus, in each cycle of cocking and firing, thelength of travel of lancet carrier 208′ can be the same. The stop 593can be located and positioned in any suitable manner such as the top,bottom, front or rear of carriage assembly 517. Note that the positionof projection stop 593 is fixed and is not moved or aligned relative tolancet carrier 208′

Carriage assembly 517 is slidably disposed with housing 106′, whichincludes a pair of guide tracks 596 on at least the right half housingportion 204′ as shown in FIG. 76. Each of tracks 596 includes stops 598a, 598 b at its opposing ends. Corresponding guide tracks (not shown)may be provided on left half housing portion 206′ as well. Projections600 extending from carriage 580 (see FIG. 75) engage tracks 596 andpermit sliding axial movement of carriage assembly 517 defined by thedistance between stops 598 a, 598 b. Carriage cover 582 includes guidesurfaces 602 that engage corresponding structure (not shown) in theinterior wall of left half housing portion 206′ to prevent movement ofcarriage assembly 517 other than in an axial direction within housing106′. Carriage cover 582 also includes an aperture 604 to revive boss592 of carriage 580 and an aperture 606 to receive a boss 608 projectingfrom carriage 580. Bosses 592 and 608 align and couple carriage 580 andcarriage cover 582.

Referring to FIG. 74, the rear end of carriage 580 includes upper andlower members 610 a and 610 b, respectively. Fingers 612 a and 612 bextend in radially opposite directions from each of upper and lowermembers 610 a and 610 b, respectively. As explained below, fingers 612a, 612 b engage depth adjuster 521 as shown in FIG. 78A.

The function of depth adjuster 521 is to permit users to adjust thepenetration depth of lancet 104 when lancing device 102′ is fired.Referring to FIGS. 78A and 78B, depth adjuster 521 includes a depthadjustment ring 614 mounted on housing 106′ for rotation about the axisof housing 106′. The forward interior portion of depth adjustment ring614 has threads 616 and the rearward interior portion depth adjustmentring 614 has circumferentially arranged detents 618. A protrusion (notshown) on housing 106′, engages detents 618 to provide discrete settingsfor depth adjustment ring 614 as it rotates about the axis of housing106′.

Carriage assembly 517 is positioned within housing 106′ so that fingers612 a, 612 b extend into the interior of depth adjustment ring 614 andengage threads 616. When a user rotates depth adjustment ring 614,threads 616 acts on fingers 612 a, 612 b to drive carriage assembly 517in sliding axial motion to and from piercing aperture 110′. Note thatthe path of travel of lancet carrier 208′ during firing of lancingdevice 102′ does not vary relative to carriage assembly 517. Thus, whendepth adjustment ring 614 is rotated in a first direction, carriageassembly 517 is moved closer to piercing aperture 110′, the entirelancet carrier 208′ and its travel path is also moved closer to piercingaperture 110′. As a consequence, sharp tip 120 of lancet 104 extendsfarther from piercing aperture 110′ when lancing device is fired, andthus penetrates more deeply into the user's skin. Similarly, when depthadjustment ring 614 is rotated in a second direction, carriage assembly517 is moved away from piercing aperture 110′, so that the entire lancetcarrier 208′ is moved away from piercing aperture 210. As a consequence,sharp tip 120 of lancet carrier 104 extends a shorter distance frompiercing aperture 110′ when lancing device 102′ is fired, and thuspenetrates less deeply into the user's skin.

It will be appreciated that manipulation of depth adjustment ring 614permits the user to adjust the ultimate penetration depth of lancet 104when lancing device 102′ is fired. The exterior of depth adjustment ring614 is accessible to users for rotation and can include indicia 620 anda knob 622 to facilitate manipulation by the user. As depth adjustmentring 614 rotates, indicia 620 are visible to the user to indicate theresulting depth setting.

Referring to FIGS. 79A and 79B, an alternative embodiment in the form ofcarriage 580′ is illustrated. This embodiment is substantially identicalto the embodiment of FIG. 72. An elongated horizontal slot 284′ isprovided in rearward half portion of lancet carrier 208′. Slot 284defines a rear wall 290′. As described above, when a user pulls cockinghandle 112′, rod 314′ draws back cocking hook 316′ which engages rearwall 290′ of lancet carrier 208′ to move lancet carrier 208′ rearward.In this embodiment, however, carriage cover 582′ includes an elongatedslot 609 a to accommodate the distal tip of cocking hook 316′. A stop609 b at the rearward end of slot 609 a limits the distance that cockingrod 314′ (and therefore lancet carrier 208′) can be pulled rearward.This is advantageous for example, when receiver 170 is mounted tocarriage assembly 517′. In that case, if lancet 104 is inserted intolancing device 102′ with removable tab 124 still attached and then pullscocking handle, there is a possibility of retracting lancet carrier 208′sufficiently rearward so that removable tab 124 engages the front end ofreceiver 170. In that case, the engagement of tab 124 with receiver 170can prevent further rearward movement of lancet 104, resulting in adisengagement of lancet 104 from lancet carrier 208′ as cocking handle112′ draws lancet carrier 208′ further back. If the stop 609 b is placedon carriage assembly 517′, the distance between stop 609 b and receiver170 is fixed, and therefore it can be assured that cocking handle 112′will not draw back lancet carrier 208′ so far as to disengage lancet104. If however, a cocking handle stop such as stop 609 b were placed onthe housing it would need to be sufficiently rearward to allow cockingthrough the full range of positions of carriage assembly 517′. Thisrearward position of a cocking handle stop fixed to housing 106′ wouldbe farther from the front end of receiver 170 as carriage assembly 517′was moved forward by depth adjustment ring 614 so that the movementrearward of lancet carrier 208′ by cocking handle 112′ would potentiallydisengage lancet 104 from lancet carrier 208′

To accommodate movement of carriage assembly 517, a trigger assembly 515is provided as shown in FIGS. 51, 80 and 81. Trigger assembly 515operates in substantially the same manner as trigger 114. Its functionscan include holding lancet carrier 208′ in, and upon actuation by a userreleasing lancet carrier 208′ from, its cocked position so that drivespring 210′ can propel lancet carrier 208′ forward.

Trigger assembly 515 includes trigger button 523 which is captured by atrigger aperture 203′ in housing 106′ and a trigger arm 626 having afront end 628 and a rear end 630 and laterally-oriented mountingaperture 632 therebetween. Trigger arm 626 is mounted by aperture 632 toboss 608 extending from carriage 580 so that trigger arm 626 can pivotabout boss 608 in see-saw fashion. Alternatively, aperture 632 can belocated near end of trigger arm 626. Note that trigger button 523 iscaptured by trigger button aperture 203′ so that it cannot move in alongitudinal direction relative to housing 106′ as carriage assembly 517is moved by depth adjustment ring 614. In contrast, trigger arm 626 ismounted to boss 608 of carriage 580, so that when carriage assembly 517moves axially within housing 106′, trigger arm 626 is also moved axiallywith carriage assembly 517.

To accommodate the axial movement of trigger arm 626, front end 628 oftrigger arm 626 is received in sliding engagement by a recess 634 intrigger button 523, so that the trigger arm 626 can be extended relativeto trigger button 523 by varying lengths as carriage assembly 517 slideswithin housing 106′. Recess 634 includes interior guide surfaces 633a-633 d which correspond in mating engagement to guide surfaces 635a-635 d, respectively on trigger arm 626, as best seen in FIG. 80. Theengagement of guide surfaces 633 a-d and 635 a-d allows trigger arm toslide axially within trigger button 523, thus allowing trigger arm 626to be extended by varying lengths when carriage assembly 517 slideswithin housing 106′. Other mechanisms such as a telescoping armstructure could also be employed to achieve this purpose.

A clip spring 636 or other suitable biasing mechanism is coupled tohousing 106′ and urges the rear end 630 of trigger arm 626 downward andfront end 628 upward, so that trigger button 523 extends through triggeraperture 203′. In this position, a latch 638 that depends from rear end630 of trigger arm 626 can engage lancet carrier 208′ to hold it in acocked position. When a user presses trigger button 523, the bias ofclip spring 636 is overcome, and trigger arm 626 pivots so that thefront end 628 moves downward and the rear end 630 moves up, effectivelyfiring lancing device 102′ by lifting latch 638 up off of lancet carrier208′ so that drive spring 210′ can propel lancet carrier 208′ towardpiercing aperture 110′.

Because trigger arm 626 moves with carriage assembly 517, the relativeaxial position of trigger arm 626 and the front end of lancet carrier208′ can be fixed. When lancet 104 is inserted into lancing device 102′,lancet 104 engages lancet carrier 208′ to both insert the rear end oflancet 104 into lancet carrier 208′ and push lancet carrier rearwardinto a cocked position, as described above. Trigger arm 626 can bepositioned so that trigger assembly 515 goes into a cocked configurationat or just after the time when lancet 104 has been inserted into lancetcarrier 208′. Thus, the cocking of trigger assembly 515 (and theattended visual indication of trigger button 523 extending throughhousing 106′) occurs after a user has successfully inserted lancet 104into lancet carrier 208′. If the cocking of trigger assembly 515 occursearlier, the user may stop inserting lancet 104 on the mistakenperception that the lancet was successfully inserted. If the position oftrigger arm 626 did not move with carriage assembly, then cocking oftrigger assembly 515 could occur at different times relative to theinsertion of lancet 104 into lancet carrier 208′ depending on the axialposition of carriage assembly 517.

Alternative Embodiment of Lancet

Referring to FIGS. 82-84, an alternative embodiment of lancet 104 isillustrated in the form of lancet 650. Lancet 650 includes needle 652whose length (excluding a sharp tip 654) is encased in an elongatedlancet body 656. A sleeve 658 slides axially over a portion of thelancet body 656 between forward position (as shown in FIG. 82), in whichit protectively surrounds the sharp tip 654 of needle 652, and arearward position (as shown in FIG. 83) in which sharp tip 654 protrudesbeyond the front end of sleeve 658.

Referring to FIG. 84, lancet body 656 includes a pair of locking membersor wings 660 a, 660 b extending from left and right lateral surfaces oflancet body 656, respectively, near the mid-section of lancet body 656.Each of wings 660 a, 660 b has a short, stiff base portion 668 a, 668 bextending radially out from lancet body 656 and a planar flexion member670 a, 670 b having a wingtip extending in generally forward directionbut at a 45° angle away from the major axis of the lancet body 656 inthe extended configuration. Wings 660 a, 660 b may be molded as part oflancet body 656.

Wings 660 a, 660 b can flap into retracted configuration by foldingplanar flexion members 670 a, 670 b from their extended position shownin FIG. 84 to a retracted position in which each flexion member 670 a,670 b is folded forward so that each flexion member 670 a, 670 b issubstantially disposed within its corresponding one of wing wells 672 a,672 b, as shown in FIG. 83. Planar flexion members 670 a, 670 b areflexible and resilient in that they can be folded into wing wells 672 a,672 b under the influence of a lateral force, but will return to theiroutward extending positions when that force is removed.

Sleeve 658 is generally tubular with an elongated inner chamber 674having a cylindrical contour to receive lancet body 656. The cylindricalcontour of inner chamber 674 is modified by the inclusion of wingengagement surfaces 678 a, 678 b, which are a pair of wide, shallowlateral grooves on opposing lateral sides of sleeve interior chamber 674that extend the length of sleeve 658. Although sleeve 658 is tubular,sleeve 658 can be made with different sectional shapes or slots (toreduce the material used to manufacture sleeve 658). In additionalembodiments, the sleeve 658 has a cross section that is one ofpolygonal, circular and ovular, as shown in FIGS. 93 a-c.

When wings 660 a, 660 b are in extended configuration (as shown in FIG.82), their wingtips span a distance greater than the diameter of innerchamber 674. If sleeve 658 moves rearward relative to lancet body 656from its protective extended position, wings 660 a, 660 b, if extended,will engage the rear end of lancet sleeve 658, blocking further rearwardmovement of sleeve 658 and in effect locking sleeve 658 in itsprotective extended position.

However, when wings 660 a, 660 b are in their retracted configuration(that is, folded into wing wells 672 a, 672 b as shown in FIG. 83), theydo not extend beyond the diameter of inner chamber 674, so that sleeve658 can slide axially over lancet body 656 without interruption. Assleeve 658 slides over wings 660 a, 660 b, each of the wings (now foldedinto wing wells 672 a, 672 b) brushes along the longitudinal extend ofelongated guide surfaces, or wing engagement surfaces 678 a, 678 b, asshown in FIG. 83.

While wings 660 a, 660 b are made of a deformable, resilient material,it is possible in rare cases that if wings 660 a, 660 b remain in afolded position for along time, they may lose resiliency and thereforenot return to their extended position when lancet 650 is ejected fromits lancing device 102 and sleeve 658 is pushed to its extendedprotected position. This may occur, for example, if lancet 104 is loadedinto lancing device 102 and is then left by the user without further usefor a long period of time, particularly if lancing device 102 is subjectto high temperature. Alternatively, if lancet 650 is used repeatedly(inserted, ejected from and re-inserted into lancing device 102), wings660 a, 660 b may lose resiliency and therefore not return to theirextended position when lancet 650 is ejected from lancing device 102.

If wings 660 a, 660 b did not return to their extended position, thenupon ejection it is possible that sleeve 658 would not be locked intoits extended position. To ensure that this does not happen, thealternative embodiment of FIGS. 82 through 84 includes a second pair oflocking members or wings 680 a, 680 b formed in left and right lateralsurfaces of lancet body 656 respectively, near the forward end of lancetbody 656 and axially spaced from the first set of wings 660 a, 660 b.Wings 680 a, 680 b are similar in structure to wings 660 a, 660 b, butare of a material that is less flexible than the material of wings 660a, 660 b. Each of wings 680 a, 680 b has a short, stiff base portion 682a, 682 b (see FIG. 84) extending radially out from lancet body 656 and aplanar flexion member 684 a, 684 b extending from the base portion 682a, 682 b in generally forward direction but at an acute angle away fromthe major axis of the lance body 656. Second pair of wings 680 a, 680 bmay be molded as part of lancet body 656.

Planar flexion member 684 a, 684 b are sized and configured so that thewing span of wings 680 a, 680 b is equal to or less than the diameter ofthe interior chamber 674 of sleeve 658, with the sleeve 658 having adiameter of less than 5 mm. During use and operation of lancet 650,second pair of wings 680 a, 680 b may be within the interior chamber 674of sleeve 658. However, as shown in FIG. 82, since the wingspan W ofwings 680 a, 680 b is equal or less than the diameter of chamber 674,they remain in a relatively relaxed state (as compared to wings 660 a,660 b) when placed into chamber 674 and are subject to little or nodeformation. As a result, wings 680 a, 680 b retain their resiliencyeven when lancet 650 remains in lacing device 102 for a long time.

When lancet 650 is ejected from lancing device 102 (as described above),sleeve 658 is pushed forward to its extended position where it surroundsneedle sharp 654. As sleeve 658 slides forward relative to lancet body656, second pair of wings 680 a, 680 b pass through a neck 686 in therear end of sleeve 658. The diameter of neck 686 is less than thediameter of chamber 674 and also less than the wingspan of wings 680 a,680 b when in an extended configuration. Wings 680 a, 680 b areconfigured so that when the rear-facing surface of planar flexionmembers 684 a, 684 b engages neck 686, it is pushed toward thelongitudinal axis of lancet body 656, in effect folding wings 680 a, 680b to permit their passage through neck 686.

Once sleeve 658 has moved fully forward, so that wings 680 a, 680 b havepassed through neck 686, then wings 680 a, 680 b return to their relaxedposition, as shown in FIG. 82. Because the diameter of neck 686 is lessthan the span of wings 680 a, 680 b, the tips of wings 680 a, 680 bengage the rear end of sleeve 658, locking it in its extended position.

Because the flexion of wings 680 a, 680 b occurs for a short intervalupon ejection of lancet 650, there is less chance that wings 680 a, 680b will lose their resiliency and fail to extend to a wingspan sufficientto lock sleeve 658 into place. In the unlikely event that wings 660 a,660 b were to fail, wings 680 a, 680 b would in all probability beoperable to prevent sleeve 658 from sliding completely out of itsextended forward position protecting needle sharp 654.

Note that one possible configuration to package lancet 650 is such thatwhen it is initially manufactured, a frangible tab similar to frangibletab 124 (see FIG. 5) holds sleeve 658 in a position where it enclosessecond wing pair 680 a, 680 b but is forward of (and locked intoposition by) first wing pair 660 a, 660 b. In this manner, if thefrangible tab is removed by a user before inserting lancet 650 intolancing device 102, wings 660 a, 660 b will prevent sleeve from movingout of an extended forward position in which it protects sharp 654.

A variety of structures may be used to perform the locking function.These other structures include, but are not limited to, pivoting membersthat pivot rather than fold into the wing wells, studs that extend outfrom the lancet body that can be pushed into a retracted position into awell in the lancet body, or barbs. For example, referring to FIGS.85-87, an alternative embodiment in the form of a lancet 690 is shownhaving a pair of barbs 692 a, 692 b which, although having a differentstructure and orientation, perform the locking function as wings 680 a,680 b.

Lancet 6990 is similar in form and function to lancet 104. Lancet 690includes a needle 694 (not shown) that is encased in elongated lancetbody 698. A sleeve 700 slides axially over a portion of the lancet body698 between an extended position in which it protectively surrounds theneedle sharp, and a rearward position in which a portion of sharpprotrudes beyond the front end of sleeve 700.

Lancet body 698 has a substantial cruciform cross section to define fourelongated guide ribs 702 a-d extending radially at ninety degreeintervals.

Sleeve 700 includes a rear end having a cruciform opening 704 to engagethe four guide ribs of lancet body 702 a-d so that sleeve 700 can slideaxially over lancet body 698.

Extending from ribs 702 a and 702 b are wings 706 a and 706 b,respectively. Wings 706 a, 706 b function substantially as wings 660 a,660 b described above. Wings 706 a, 706 b are configured as an inclinedplanar flexion member extending from and integral with each of ribs 702a and 702 b, respectively.

Barbs 692 a, 692 b are aligned with ribs 702 c and 702 d, respectively.Barbs 692 a, 692 b have flexible portions 708 a and 708 b forming in aV-shaped configuration, with the point of the V facing rearward. Therearward ends of portions 708 a, 708 b define a width that is wider thanthe portions 710 a and 710 b of cruciform opening 704 that receivesbarbs 692 a, 692 b when sleeve 700 moves rearward relative to lancetbody 698. However, the inter chamber of sleeve 700 is sized toaccommodate barbs 692 a, 692 b without deformation.

When lancet 690 is initially manufactured, sleeve 700 can be positionedrelative to lancet body 698 so that barbs 692 a, 692 b are within theinterior chamber of sleeve 700, which includes opposing longitudinalengagement surfaces 712 a and 712 b (see FIGS 86 and 87) sized andpositioned to accommodated barbs 692 a, 692 b, thus permitting sleeve700 to slide axially relative to lancet body 698. When lancet 690 isejected from lancing device 102, for example, sleeve 700 is pushedforward until barbs 692 a, 692 b are forced through portions 710 a and710 b of cruciform opening 704 in the rear of sleeve 700. Although theopening portions 710 a, 710 b are more narrow than barbs 692 a, 692 b,barbs 692 a, 692 b are configured so that when the rear-facing surfaceof each flexible portion 708 a, 708 b engages opening portions 710 a,710 b, barbs 692 a, 692 b are squeezed to in effect pinch the barbs 692a, 692 b and permit their passage through the opening portions 710 a,710 b.

Once sleeve 700 has moved fully forward, so that barbs 692 a, 692 b havepassed through opening portions 710 a, 710 b, then flexible portions 708a, 708 b return to their relaxed position, as shown in FIGS. 85 through87. Because the width of opening portions 710 a, 710 b is less than thewidth of barbs 692 a, 692 b, barbs engage the end of sleeve, locking itin its extended position.

Alternative Embodiment of Ejection Locking Member

Referring to FIGS. 88 through 92, an alternative embodiment of lancingdevice 102′ is described in which an ejection locking member 750 isprovided. Ejection locking member 750 performs a function similar tothat of ejection locking member 524, described above, namely to preventforward movement of lancet carrier 208′ when lancet 104 is ejected fromhousing 106′. Ejection locking member 750 operates in conjunction withan ejection actuator 516′ similar in construction and function toejection actuator 516 described above.

Referring to FIG. 88, ejection locking member 750 is made of a wire-likemetal (although plastic or other materials can be used) which isconfigured to define V-shaped blocking portion 752 formed by twoelongated members 754 and 756 at approximately right angles to eachother, each lying in a common horizontal plane. Extending verticallyfrom the distal end of member 754 is an elongated guide arm 758.Extending vertically from the distal end of member 756 is an elongatedanchor arm 760. Anchor arm 760 terminates in a Z-Shaped anchor portion762. Ejection locking arm is mounted to a carriage 580.

Referring to FIGS. 89 through 92, the interrelationship of ejectionlocking member 750, carriage 580 and lancet carrier 208′ and ejectionactuator 516′ is shown. Ejection locking member 750 is installed oncarriage 580 so that anchor portion 762 is secured by a receiving notch764 on carriage 580 (seen in FIG. 91 and 92) and guide arm 758 isslidably engaged by a vertical notch 766 in carriage 580. In thisconfiguration, blocking portion 752 is interposed in the path of lancetcarrier 208′, so that the forward movement of lancet carrier 208′ alongits longitudinal axis is blocked, as shown in FIGS. 89 and 92. Note thatfor clarity carriage 580 is not illustrated in FIG. 89.

Referring to FIGS. 90 and 91, during the loading, cocking and firingoperations of lancing device 102′, ejection actuator 516′ is in itsrearward neutral position, where an engagement surface 768 on theright-hand side of ejection actuator 516′ engages blocking portion 752to push it out of the path of lancet carrier 208′. Notch 766 providesclearance to allow movement of guide arm 758 when this movement occurs.Note, however, that in this configuration, a torsion force is imposed onejection locking member 750 at point 768 (FIG. 88), as member 756rotates slightly about the longitudinal axis of anchor arm 760.

When lancing operations are completed, the user will actuate ejectionactuator 516′ as described above to remove lancet 104 (not shown in FIG.88 through 92), resulting in the forward movement of ejection actuator516′ as shown in FIG. 92. As ejection actuator 516′ moves forward in thedirection of arrow A, engagement surface 770 no longer engages blockingportion 752. The torsion force imposed at point 768 causes member 756 torotate in spring-like fashion to its neutral, untensioned state, thusmoving blocking portion 752 in the direction of arrow B to block thepath of lancet carrier 208′ and thus prevent the forward movement oflancet carrier 208′ during the ejection of lancet 104.

An advantage of ejection locking member 750 is that its neutral positionis blocking lancet carrier 208′. Thus when ejection actuator 516′ ismoved forward, the spring-like action of ejection locking member 750provides for reliable and quick transition to a blocking position.

The above-mentioned embodiments have been described in order to alloweasy understanding of the present invention. The invention is not to belimited to the disclosed embodiments but, on the contrary, is intendedto cover various modifications and equivalent arrangements includedwithin the spirit and scope of the appended claims, which scope is to beaccorded the broadcast interpretation so as to encompass all suchmodifications and equivalents structures as is permitted under the law.

1. A lancet, comprising: an elongated body having therein a needleterminating in a sharp tip; a sleeve having a front end and a rear end,the sleeve being disposed about at least a portion of the elongated bodyand movable relative to the elongated body between a forward position inwhich the sharp tip is protectively surrounded by the sleeve and arearward position in which the sharp tip projects from the front end ofthe sleeve; and a first locking member extending from the elongated bodyat a location intermediate the forward and rearward positions, the firstlocking member having an extended configuration in which the firstlocking member engages the sleeve to prevent the sleeve from movingrearward, and a retracted configuration in which the first lockingmember does not engage the sleeve to prevent the sleeve from movingrearward; wherein at least a portion of an interior of the sleeve isconfigured to contain the first locking member in the retractedconfiguration when the sleeve moves over the first locking member. 2.The lancet of claim 1 wherein the first locking member extends from theelongated body in a generally forward direction forming an angle with amajor axis of the elongated body when the first locking member is in theextended configuration.
 3. The lancet of claim 2 wherein the firstlocking member is substantially parallel to the major axis of theelongated body when the locking member is in the retractedconfiguration.
 4. The lancet of claim 3 wherein the elongated bodycomprises a well positioned to receive the first locking member in theretracted configuration.
 5. The lancet of claim 1 wherein the interiorof the sleeve comprises an elongated guide surface arranged to containthe first locking member in the retracted configuration when the sleevemoves over the first locking member.
 6. The lancet of claim 1 whereinthe rear end of the sleeve defines a rear aperture configured to permitentry of the first locking member into the interior of the sleeve whenthe first locking member is in the retracted configuration and toprevent entry of the first locking member into the interior of thesleeve when the first locking member is in the extended configuration.7. The lancet of claim 1 wherein the interior of the sleeve has a crosssection that is one of polygonal, circular and ovular.
 8. The lancet ofclaim 1 wherein the first locking member is comprised of a resilientdeformable material that urges the first locking member to the extendedconfiguration when the first locking member is moved to the retractedconfiguration.
 9. The lancet of claim 1 wherein the sleeve has a widthless than 5 mm.
 10. The lancet of claim 1 wherein the first lockingmember comprises a pair of wings radially extending from opposing sidesof the elongated body.
 11. The lancet of claim 1, further comprising asecond locking member axially spaced from the first locking member, thesecond locking member movable between an extended configuration and aretracted configuration and comprised of a resilient flexible materialthat urges the second locking member to the extended configuration whenthe second locking member is moved to the retracted configuration;wherein the rear end of the sleeve defines a rear aperture that isconfigured to permit entry of the second locking member into theinterior of the sleeve when the second locking member is in theretracted configuration and to prevent entry of the second lockingmember into the interior of the sleeve when the second locking member isin the extended configuration; and wherein the interior of the sleeve isconfigured to permit the second locking member to return to the extendedconfiguration after entry into the interior.
 12. The lancet of claim 11wherein the second locking member is of a geometry that is less flexiblethan a geometry of the first locking member.
 13. The lancet of claim 11wherein the second locking member comprises at least one barb.
 14. Thelancet of claim 1 wherein a distal end of the first locking member inthe extended configuration is spaced apart from the elongated body by afirst distance, and a distal end of the first locking member in theretracted configuration is spaced apart by a second distance, whereinthe second distance is less than the first distance.
 15. A lancetassembly, comprising: a lancet in accordance with claim 1; a housinghaving a user-engaging end that defines a piercing aperturetherethrough, the piercing aperture sized to allow insertion of thelancet therethough; and a lancet engagement mechanism adapted to receivethe lancet when the lancet is inserted through the piercing aperture sothat substantially all of the lancet is enclosed by the housing.
 16. Alancet, comprising: an elongated body having therein a needleterminating in a sharp tip; a sleeve having a front end and a rear endand disposed about at least a portion of the elongated body, the sleevelocated at an initial position relative to the elongated body so thatthe sharp tip is disposed within the sleeve; a first locking memberextending from the elongated body at a location outside of the sleeveand having an extended configuration in which the first locking memberengages the sleeve to prevent rearward movement of the sleeve and aretracted configuration in which the first locking member does notengage the sleeve to prevent rearward movement of the sleeve; and asecond locking member axially spaced from the first locking member andextending from the elongated body at a location within the sleeve. 17.The lancet of claim 16 wherein the sleeve is movable forward relative tothe elongated body from the initial position to an ejection position,and wherein the second locking member is configured to engage the rearend of the sleeve to prevent rearward movement of the sleeve when thesleeve is moved to the ejection position.
 18. The lancet of claim 16,further comprising a tab removably coupled to the elongated body andextending into the front end of the sleeve to surround the sharp tip.19. The lancet of claim 16 wherein an interior of the sleeve isconfigured to contain the first locking member in the retractedconfiguration when the sleeve moves over the first locking member.
 20. Amethod of using a lancet having an elongated body with a needle thereinterminating in a sharp tip, a sleeve disposed about at least a portionof the elongated body and movable relative to the elongated body, and alocking member having an extended configuration and a retractedconfiguration, the method comprising: positioning the sleeve in aforward position in which the sharp tip is protectively surrounded by atleast a portion of the sleeve; placing the locking member in theextended configuration to prevent rearward movement of the sleeve;loading the lancet into a lancing device; moving the locking member intothe retracted configuration before firing the lancing device to permitthe sleeve to move rearward over the locking member; and containing thelocking member in the retracted configuration while the sleeve movesover the locking member.